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Full text of "Birds of California in relation to the fruit industry"




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Historic, archived document 

Do not assume content reflects current 
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Issued November 11, 1907. 

U. S. DEPARTMENT OF AGRICULTURE 

BIOLOGICAL SURVEY BULLETIN No. 30 

C, HART MERRIAM, Chuf 



BIRDS OF CALIFORNIA 

IN RELATION TO THE 
FRUIT INDUSTRY 



PART I 



By F. E. L. BEAL 

Assistant, BioTogical Survey 




WASHINGTON 
GOVERNMENT PRINTING OFFICE 

19o7 



rical Survey. U. S. Dept. of Agriculture 



Plate I. 




CALIFORNIA BUSH-TIT ( PSALTRIPARUS MINIMUS CALIFORNICUS). 



issued November 1 1 . r.«>, . 

U. S. DEPARTMENT OF AGRICULTURE 

BIOLOGICAL SURVEY BULLETIN No. 30 

C. HART MERRIAM, Chief 



BIRDS OF CALIFORNIA 

IN RELATION TO THE 

FRUIT INDUSTRY 



PART I 



Iiy F. E. L. BEAL 

Assistant, Biological Survey 




WASH I \ GT< »\ 

GOVERNMENT PRINTING OFFICE 
1907 



LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 

Biological Survet, 

Washington, I). C, July 27\ 1907. 
Sir: T have the honor to transmit herewith as Bulletin No. 30 
of the Biological Survey, Part I of a report on the Birds of Cali- 
fornia in Relation to the Fruit Industry, by F. E. L. Beal. Fruit 
raising in California is a great and growing industry, and the relation 
birds bear to it is important. The investigations embodied in the 
present report were undertaken with a view to the accurate deter- 
mination of the economic status of every species of California bird 
that inhabits orchards, in order that it may be possible for the fruit 
raiser to discriminate between friends and foes; and for the added 
purpose of suggesting remedial measures for the protection of fruit 
from destructive species. As expected, the strictly insectivorous 
birds prove to be almost wholly beneficial, by far the greater per- 
centage of the insects eaten by them being injurious kinds. They are 
hence allies of the orchardist and their presence in and near orchards 
should be encouraged in every way. Of the species addicted to fruit 
eating, not one was found to make its diet wholly, or even chiefly, 
of fruit ; and the fruit eaters, with possibly the exception of the 
house finch, are found to feed upon weed seeds and noxious insects 
to such an extent as to fully offset their destructive propensities. 
Respectfully, 

C. Hart Merriam, 
Chief, Biological Survey. 
lion. James Wilson, 

Secretary of Agriculture. 

3 






CONTENTS. 



Page. 

Introduction •_ 7-13 

Bouse finch _. 13-2:: 

Western tanager 23-2(5 

Swallows 26-33 

Cliff swallow 28-30 

Western barn swallow 30-32 

Violet green swallow 32-33 

California shrike 33-38 

Vireos 38-42 

Western warbling vireo 39-40 

( Jassin vireo 40-41 

Button vireo 41-42 

Warblers ' 42-52 

Audubon warbler 43-46 

Myrtle warbler 1 4d 

Townsend warbler 4b— 17 

Summer warbler 47-4!) 

Western yellowthroat 49-50 

Orange-crowned warbler 51 

Golden pileolated warbler 51-52 

Western mocking bird 52-55 

California thrasher 55-56 

Wrens 57-66 

Bewick wren ■ 57-60 

Western house wren 60-62 

Western marsh wren 62-64 

Cactus wren , 64-65 

Other wrens <;r>-<;i; 

California creeper _ - 66 

Nuthatches and titmice 66-80 

Pygmy nuthatch 67-68 

Plain tit 68-70 

Chestnut-sided chickadee 70-71 

Wren tit 71-74 

California hush tit 74-80 

Kinglets T ■ 80-84 

Ruby-crowned kinglet 81-84 

Western golden-crown kinglet 84 

Gnatcatchers 84-86 

Russet-back thrush - 86-92 

Hermit thrush 92-93 

Western robin 93-97 

Western bluebird 97-100 

5 



ILLUSTRATIONS 



Page. 

Plate I. California bush tit Frontispiece. 

II. Seeds of common weeds eaten by the linnet 1(5 

III. Audubon warbler 42 

IV. Cactus wren (i4 

V. Plain tit 68 

6 



BIRDS OF CALIFORNIA IN RELATION TO THE FRUIT 
INDUSTRY PART I. 



INTRODUCTION. 

Iii response to numerous complaints from fruit growers concerning 
depredations by birds in orchards and vineyards in the Pacific coast 
region, investigation oi the subject was undertaken by the Biological 
Survey severa] years ago. In conducting thi> investigation the 

writer spent about nineteen months in California, including the fruit 
seasons of 1901. 1903, and 1906, during which time he visited the 
most important fruit-growing regions of the State, inspected hun- 
dreds of orchards, and interviewed many fruit growers. Kindness 
and courtesy were everywhere met with, and every facility was ex- 
tended by orchardists for the acquisition of information, even to a 
suspension of the customary rules with regard to trespass and -hoot- 
ing on private grounds. In addition to the knowledge gained by 
field observations, stomachs of all the species of Pacific coast birds 
economically valuable have been collected, examined, and their con- 
tent- recorded. 

When depredations are so widespread and involve so many differ- 
ent species of birds, a thorough knowledge of the nature and extent 
of the damage done and of the attending circumstances is of great 
importance. Next in importance i^ a knowledge of the conditions 
that obtain in fruit-growing regions where depredations by bird- do 
not occur. This information should enable the fruit grower to adjust 
condition- in hi- own case so a- to mitigate if not wholly prevent 
the evil. 

In the following pages much stress is laid on the nature of the 
yearly or seasonal food of some of the more important species of 
birds, since it often happens that certain birds are more or less harm- 
fid to a particular crop of fruit, and yet the year through, all things 
considered, do more good than harm. It niu-t not be forgotten in 
this connection that there are very few bird- whose habit- are wholly 
beneficial. Most of them are neither wholly beneficial nor wholly 
injurious. They are beneficial at some seasons and injurious at 
others. In some localities they are deservedly praised \'nv benefits 
conferred; in other- the >ame species are condemned for destructive 

7 



8 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

habits. With the evidence all in, it is usually possible for the farmer 
to properly estimate the status of any given species with reference 
to his own farm and his own interests and to adopt measures 
accordingly. 

It can not be too thoroughly insisted that sound public policy 
everywhere forbids the destruction of birds on a large scale for the 
purpose of protecting orchard fruits. Wholesale slaughter of birds 
in the supposed interest of the orchardist is fortunately rare and 
often proceeds from a mistaken idea of their economic relations. 
When it is understood that the damage by a certain species is local 
and exceptional, that the birds in question are on the whole bene- 
ficial and that their destruction will be a loss to the State, the 
farmer and the orchardist are usually willing to adopt less drastic 
measures in defense of their crops and to spare the birds for the 
sake of the general weal. 

STATUS OF BIRDS IN NEWLY SETTLED REGIONS. 

When a new country is settled, large areas are plowed and brought 
under cultivation. In the process great numbers of native shrubs, 
weeds, and grasses are destroyed, and various new and exotic plants 
and trees are substituted. Coincident with this change in the vege- 
table life, and as a necessary consequence of it, great changes in the 
conditions and distribution of animal life take place. Some species 
are restricted in distribution and greatly reduced in numbers, or even 
exterminated, while others become more abundant and more widely 
dispersed. The reduction in numbers may occur from actual killing 
by man, from the destruction of natural breeding sites through 
clearing:, and from a diminution of food traceable to the same cause. 
The results are exactly the opposite when cultivation and planting 
afford a more abundant supply of food, greater facilities for breed- 
ing, and better protection from enemies. The natural result of such 
conditions is a marked increase in number of the favored species, 
and this increase probably explains the great devastation of crops 
by birds that occurred on the Atlantic seaboard soon after the first 
settlements, and then successively in the States to the westward as 
these were gradually settled. 

The early day- of agriculture in California offer an interesting case 
in point. When the native grasses and weeds of the fertile valleys 
were destroyed to make room for grain, many species of birds, 
notably blackbirds and quails, were suddenly deprived of their natural 
subsistence and in place of it were supplied with an abundance of 
new and nutrition- food. Naturally they preferred the cultivated 
grains (wheat, barley, and oats) to the wild .oats (Avena fatua) upon 
which they had largely depended. Still later, when many of the 



INTRODUCTION. 9 

grain fields gave way to extensive orchards, which gradually crept 
up the hillsides and into the canyon-, other species of birds began 
to utilize the new kind- of food and also the safe nesting sites 
afforded by orchard tree-. Species that previously attracted Little 
attention soon increased in numbers because of the increased food 
supply, additional facilities for nesting, and the protection afforded 
by man, who killed or drove away their natural enemies. A> a result, 
some of them suddenly became of great economic importance, owing 
to their increased numbers and destructive habits. 

MIGRATION OF BIRDS. 

Owing to its extent and varied topography, California is rich in 
birds, both in species and individuals. Here altitude and topog- 
raphy, as well as latitude, govern climate. This fact leads to many 
peculiarities in distribution and complicates the study of birds in 
their economic and other relations. The movements of birds, too, are 
more complex than in the eastern part of the United States. The 
regular migration north in the spring and south in the fall, which is 
the rule over the greater part of the country, is here supplemented. In 
the case of man}^ species, by a migration from the mountains, where 
they breed, to the valleys, where they winter. Besides the regular 
migrations, at times remarkable incursions of a single species take 
place. Such was the flight of mountain tanagers {Piranga ludo- 
viciana) in the valleys in May, 1896. In several parts of California 
these birds appeared in immense numbers in localities where pre- 
viously they had been rarely observed. Their appearance coincided 
nearly with the ripening of the cherry crop, to which in some places 
they did much damage in spite of the fact that great numbers of 
them were -hot. 

CAUSES OF DEPREDATIONS BY BIRDS. 

The failure of customary food supply sometimes leads birds to 
forage upon crop- which they do not commonly eat. This may be 
the explanation of the depredations of robins in the fall and winter 
of 1900-1001, when thousands of these birds pillaged the olive 
orchards in Santa Clara Valley, the region about Santa Barbara, and 
other parts of California. In that year it was as much as the olive 
growers could do to save part of their crop. Since then no case of 
excessive loss of olives has been reported, though occasionally some 
damage has been done. 

The amount of damage inflicted by birds upon a crop often depends 
upon the surroundings. In the case of orchard- in the midst of a 
treeless plain depredation- are mostly confined to such bird- as nest 
in them, but they may be visited and damaged by others during 



10 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

migration. On the other hand, fruit grown near or in brushy can- 
yons or on wooded hills is taken by birds that live in such places ; or 
a stream flowing through a region of orchards may harbor in the 
shrubbery on its banks many birds that do not live in the orchard 
itself. 

Hence depredations by birds may arise: (1) From the settlement 
of a region and consequent introduction of new crops, accom- 
panied by a diminished supply of natural food, destruction of ene- 
mies, and a general change of natural conditions; (2) from failure 
of the normal food supply, causing migration in search of food, or 
an attack upon some product which the species does not usually eat; 
(3) from proximity to a particular crop, in which case the bird natu- 
rally eats that which is most available. 

COXDITIOXS IX CALIFORNIA COMPARED WITH THOSE IX THE EASTERN 

STATES. 

Before proceeding to a consideration of particular birds, one point 
should be specially noted in connection with the subject of the rela- 
tion of birds to fruit in California. Those parts of the State where 
fruit is grown are not so well supplied with wild fruits on which 
birds feed as are the fruit-growing areas of the Eastern States, or 
even of those farther north on the Pacific coast. While California 
has an abundance of wild berries which serve as food for birds, they 
do not commonh T grow near orchards and vineyards. 

In the Eastern States a plentiful supply of fruit, as acceptable to 
birds as the best products of the orchard or garden (perhaps more 
acceptable), is usually present in pastures and along roadsides, so 
that it is only where wild fruits are exterminated by cultivation that 
birds are forced to eat cultivated kinds. So abundant is wild fruit 
in some region-, a- in the United States east of the Alleghanies, that 
;t is safe to say that thousands of bushels of blackberries and rasp- 
berries which grow wild everywhere annually fall to the ground and 
rot, in spite of the fact that great quantities are gathered and eaten 
by man a- well as by birds. The same is true of blueberries ( Vac- 
cinium) and huckleberries (Gaylussacia), which are so abundant in 
a wild -late that in their season they appear in the markets of most 
of I he cities and large town-, and are eaten in every country home in 
the region where they grow. In addition to these are several species 
of .logwood (Cornus), holly (Ilex), cherry (Prunus), Viburnum, 
and many other-, all of which are freely eaten by birds. 

Although many of these fruit-bearing shrubs are represented in 
California by related species, they usually grow in the mountains 
remote Prom fruit-growing districts. Tn fact, the elderberry (Sam- 
bucus), the introduced pepperberry (Schinus molle), and an occa- 
sional mistletoe berry are the only important uncultivated fruits 



INTRODUCTION. 11 

that appear in the stomachs of California orchard birds. On the 
other hand, in the Ma-tern States more than 10 species of wild 
fruits have been Pound in the stomachs of a single species the 
Eastern robin. In the genera] dearth of wild fruits on the horti- 
cultural areas of the Pacific coast it is not surprising that when 
dome-tic fruits were first cultivated there the birds gave them a 
warm welcome, and the orchardist's crops suffered accordingly. 

Another reason why birds attack fruit in California more than in 
the regions farther east is the dryness of the summers, juicy fruits 
proving an acceptable substitute for water. To secure enough water 
for their riecessil ies Cah fornia birds must often fly several miles, while 
in the Eastern State- localities are few in which water can not he 
obtained within a few rods. In confirmation of the theory that in 
attacking fruit liquid for slaking thirst is sought by birds as much as 
food, it may he stated that much of the injury done to small juicy 
fruit- in California, such a- grapes and cherries, consists of simple 
puncture- in the skin, through which apparently nothing but juice 
ha- been drawn. 

PROTECTIVE MEASURES. 

It would appear most desirable that some of the available fruit- 
bearing trees, the fruits of which are of little or no value to man. but 
which to bird- are even more acceptable than cultivated kinds, should 
be freely introduced into California for the protection of the orchard- 
ist. That some of them would thrive there hardly admits of doubt. 
Morus alba, the Russian mulberry, is one of the best, the fruit having 
little value unless as food for birds. All fruit-eating species are fond 
of it. Both the red and the black mulberries are equally sought after, 
but are not often planted for birds alone. The paper mulberry 
( Broussom tia pa pyrifi ra ) is hardy and is a favorite bird food. Sev- 
eral species of Prunus or cherry, including the choke cherry (P. vir- 
giniana), and especially it- western form (P. demissa), the black 
cherry (P. serotina) ,and the bird cherry (P.pennslyvanica) are of great 
value in protecting fruit crops, birds almost invariably selecting their 
fruit in preference to the cultivated varieties. There are also several 
ornamental varieties of cherries, such a- the European birdcherry (P. 
a r'ni in). l\ />< inhihi of Japan, and P. sphmrocavpa of Brazil, which 
are hardy, the latter in warm regions only, and valuable a- bird foods. 
Both the pepper tree. Schinus m<>lh . and the elder. Sambucus, now 
abundant in California, are eaten l>v many bird.-, and both may be 
planted near orchards with the certainty that they will serve to pro- 
tect them. 

Another measure recommended for the protection of orchard fruit 
i- a supply of water accessible to the bird-. Drinking place- for 
birds in every large orchard would tend to reduce the injury done to 



12 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

fruit, and would serve the added purpose of attracting insectivorous 
birds to the locality. Birds undoubtedly select breeding places with 
reference to the convenience of food and water, and a constant supply 
of the latter attracts to the vicinity many desirable species. The 
insectivorous kinds would more than pay the orchardist for his trouble 
in their behalf by feeding upon the insects that injure his tree-: 
while fruit-eating species, like the linnet, being able to quench their 
thirst with water, would not be compelled to resort to fruit for this 
purpose. 

The writer once observed a leaky hydrant situated between two 
rather extensive areas of orchards. The little pool maintained by the 
drip of this pipe was almost constantly surrounded by birds which 
all the time were coming and going, so that the number that visited 
it each day must have been well up in the thousands. An arrange- 
ment for this purpose need be neither elaborate nor expensive, and 
would serve a useful purpose. 

READJUSTMENT OF CONDITIONS. 

In relation to the destruction of crops by- birds in a comparatively 
newly planted region, experience everywhere shows that after a time 
there is a partial readjustment of conditions, so that inroads by birds 
become much less common or wholly cease. On the Atlantic side 
of the continent at the present time, with the exception of the 
ravages of bobolinks in the rice fields of the southeastern coast States, 
few if any cases are known of the annual destruction of crops by 
birds, while during the first half of the nineteenth century the 
several species of blackbirds were a constant menace to grain. Pres- 
ent immunity results from the fact that increased density of popula- 
tion has destroyed the nesting sites and reduced the numbers of some 
of the most noxious birds. This readjustment of conditions is likely 
to take place sooner or later in all cases where the balance of nature 
is disturbed, but in most cases the process may be hastened by the 
adoption of measures like the ones above mentioned. 

DAMAGES BY -BIRDS GENERALLY. 

Study of a number of cases of serious damage by birds leads to the 
conclusion that as a rule such damage is due to the concentration of 
a great number of birds within a limited area, usually of a single 
species or several closely allied ones. If the birds are seed eaters, 
they \ isil the grain fields and leave ruin and destruction in their path; 
if fruit lovers, they seek the orchard and play havoc with the crop. 
Instances of this kind are the raids of bobolinks in the rice fields of 



HOUSE PINCH. 13 

the southeastern Atlantic coast, of the blackbirds in the grain fields 
of the Mississippi Valley, and of the Linnets in the iVnit orchards of 
California. It is seldom that complaints arc made of bird- in gen- 
eral; one or a few species arc usually the culprits, the reason for 

which is evident — too many individuals of the same species in one 
locality eating the same things. But when many species are present 
in normal numbers, such a variety of tastes is to be gratified that no 
one kind of food is unduly drawn upon. 



BIRDS THAT [NJTJRE 1-TM IT IN CALIFORNIA. 

When a fruit grower in northern California is asked what birds are 
most injurious to his crops, he almost invariably mentions first the 
linnet, or house finch; then successively the blackbird, the oriole, the 
grosbeak, and the thrush. Or, if his ranch is in a narrow valley or 
canyon, or near wooded hills, he may place the California jay or the 
quail after the linnet as the next worst enemy to fruit. 

The writer is pleased to be able to testify to a healthy state of 
feeling on the part of the great majority of California fruit growers 
toward the bird population. While many of them stated that they 
-till sn tiered loss, none advocated measures for the extermination, or 
even the material decrease, of birds. The feeling seems to be prac- 
tically universal that birds as a class, notwithstanding their sins, 
still do more good than harm. "We can't get along without the 
birds," was the sentiment voiced by many and realty indorsed by all. 

HOUSE FINCH. 

(Carpodacus mexicanus frontalis.) 

The house finch, or linnet, has been perhaps the subject of more 
complaint on the score of destroying fruit in California than all 
other species of birds together. This bird occurs on the western 
coast of the United States from Mexico northward to Oregon, and 
extend- eastward to the western edge of the Mississippi Valley. 
Except in the mountains, it is a resident throughout most of Cali- 
fornia, but in certain parts of the northern half of the State it dis- 
appears for a few month- during the winter season. In the southern 
half and in the warm sheltered valleys of the north it is always 
present. It is a hardy, vigorous species, well able to take care of 
itself and maintain it- ground wherever it obtains a foothold. It is 
a prolific breeder, raising several broods in the season, and apparently 
has no enemy (except man) thai exercises any perceptible restrictive 
influence 1 upon its increase and distribution. It take- kindly to the 
presence of man. and utilizes his improvements for shelter and food. 



14 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

DESTRUCTION OF FRUIT. 

Observations in orchards show that in the fruit season the linnet 
is not backward in taking what it considers its share of the crop, and 
as it spends much of the time there, field observations alone would 
lead to the conclusion that fruit was its principal article of diet. 
Examination of the stomach contents, however, proves that such is 
not the case, and when we find how small is the relative percentage 
of fruit eaten, it seems strange that its fruit -eating proclivities should 
have attracted so much attention. But it must be borne in mind that 
the bird is wonderfully abundant, which is one of the primary condi- 
tions necessary for any species to become injurious. 

Like most fringilline birds, the linnet has a strong, conical beak, 
with which it can cut the skin of the toughest fruit and reach the 
pulj^. 'While such an instrument is very effective in attacking fruit, 
this is evidently not the use for which nature primarily designed it. 
It is customary to divide passerine birds roughly into two groups, 
the hard-billed and the soft-billed species, the former of which are 
supposed to feed on seeds while the latter subsist upon fruit and 
insects. From the standpoint of this classification the linnet would 
appear to be most emphatically a seed eater, and examination of the 
contents of stomachs of the species confirms the correctness of this 
view. Seeds of plants, mostly those of noxious weeds, constitute about 
seven-eighths of its food for the year, and in some months amount to 
much more. In view of this fact it seems strange that the house 
finch has acquired such a reputation for fruit eating, and it can be 
explained only upon the principle already laid down that in the fruit 
districts the bird is too numerous for the best economic interests. 
AVhile each house finch eats but a small modicum of fruit, the aggre- 
gate of all that is eaten or destroyed by the species is something 
tremendous. 

Moreover, it must be noted that not all of the fruit destroyed is 
eaten. Only one peck from the strong bill is necessary to break the 
skin of the pear, peach, or cherry, and the fruit is spoiled; the linnet 
by no means invariably visits the same individual fruit a second time 
to finish it. but often attack- a fresh one at each meal. This i- proved 
by the large number of half-eaten fruits, either on the tree or on the 
ground beneath. 

In large orchard-, however, complaints against the linnet are fewer 
than formerly. Here the damage is more widely distributed and con- 
sequently less noticeable than when confined to a few trees. It is 
probable that the area of orcharding has increased more rapidly than 
the linnet-, so thai the proportional injury is less. At present the 
chief complainants are the owner- of -mall town lot-, where a few 
tree- ;ire grown to supply fruit for home use. As linnets are usually 



EOTJSE PINCH. L5 

more aumerous in tillages and suburbs than in the country, trees in 
gardens are often i ntirely stripped. 

i\.n i:v TO i in it m ns. 

It is a little singular that formerly most of the complaints againsl 
the linnet were that it destroyed the buds and blooms of fruit trees 
instead of the fruit itself. Thus in L886 Mr. R. P. Chandler, of 
Riverside, San Bernardino County. wrote: 

The bird which is commonly known as the linnet, or crimson house finch, lias 
been observed to do greal injury to the apricol crops of this section by feeding 
on the fruit buds from the time they begin to swell until the trees are in bloom. 
Two years ago my entire apricot crop was destroyed by the above birds, and I 
took the opportunity to establish the facts of the case by shooting a large num- 
ber for the purpose of examination. A greal many of the birds that svere shot 
had small hits of buds, etc.. stnrk on their hills by the gummy substances of the 
fruit buds. A further examination would invariably result in finding each and 
every hint's stomach filled with buds. 

The -ante year J. C. Galloway, of Tustin, Cal., stated: 

The common linnet does great injury to the buds of the apricot, eating out 
the center Mini destroying .ill the fruit buds on the tree in many cases, usually 
in January and February, in this latitude. 

William Proud, of Rancho Chico, Cal., accuses the linnet of eating 
both buds and fruit. He says: 

The burion, house finch, or linnet, is by far the most pernicious bird we have 
to deal with in the orchard. He arrives in March and immediately commences 
his ravages on the buds of the cherry, peach, plum, persimmon, etc The first 
cherry showing a red cheek is sampled by this most rapacious little bird. Then 
comes the fruit of the apricot, peach, and tig. For the latter he shows a decided 
partiality. When the fruit crop is exhausted he immediately turns his atten- 
tion to all kinds of millets, sorghum, Egyptian corn, and other small seeds. 

As showing how destructive the bird is to fruit, especially in small 
orchard-, the following is quoted from Dr. T. S. Palmer, then at 
Berkeley, Alameda County, Cal.: 

The crimson house finch is the only bird that does any considerable damage 
to fruit. As soon as the cherries begin to ripen the birds keep .-lose watch of 
the trees, and if the fruit is not gathered as soon ;is ripe they soon dispose of ;i 
large portion of it. In our garden there are about a dozen cherry trees of 
various kinds, and if not very closely watched, within a week or two from the 
time when the fruit first begins to ripen almost every tree will he completely 
stripped. Of course, in a large orchard the damage would not be so noticeable, 
l-ut still mighl he considerable. Later in the season when the cherries are 
gone, the finches attack the plums and pears. 

F. II. Holmes, of Rio Vista, Solano Count}', Cal., under date of 
September, L886, states : 

Our worst fruit post is the crimson house finch, which, on account of its 
abundance and familiarity, it is impossible to scare off. They injure mostly 
cherries, tigs, berries, peaches, and apricots. They often only peck each fruit 



16 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

a little, and then the bees and wasps take bold and finish tbe work. * * * 
Birds that destroy tbe earlier fruits are generally regarded as tbe greater 
nuisance, particularly to tbe farmer who has not a very extensive orchard. 
Where fruit is bandied as soon as it is in tbe proper condition, or for an orchard 
of from ten to one hundred acres or more, 1 have never seen these birds plenti- 
ful enough to do a great amount of damage. In some parts of the State I 
presume they might do more. 

In regard to the habit of the linnet of eating ripe fruit, Dr. A. K. 
Fisher says: 

In this valley [Owens], both at Independence and Lone Pine, the species 
[the linnet] was found to be very destructive to the ripened peaches during the 
middle of August. Flocks of birds occurred in the orchards, and in some 
places hardly an example of the ripe fruit could be found which was not more 
or less mutilated. A number of birds shot in the peach orchards at Lone Pine 
bad little except the pulp of this fruit in their gullets or stomachs. It was 
known as the ' peach bird.' a 

Examination of linnet stomachs does not reveal any very consid- 
erable number of blossom buds, and it is probable that but little of 
the alleged mischief to fruit blossoms is done by this bird. Moreover, 
it may be stated that in most cases budding by birds does little, if 
any, damage. It is only in very rare instances that birds take all 
the buds from a tree, or even enough to cause considerable loss. On 
the contrary, buds are usually superabundant, and budding, whether 
by birds or by man, is frequently beneficial, relieving the trees from 
excessive bearing and markedly improving both size and quality 
of fruit. 

THE LINNET NATURALLY A SEED EATER. 

Before the settlement of the Pacific coast region it is evident that 
the linnet must have subsisted almost entirely upon the seeds of 
plant- growing wild in the valleys and canyons. With the advent 
of civilization two new articles of food were presented — grain and 
fruit. It would seem natural for the linnet, especially equipped as 
the bird is to extract the kernel of seeds, to have chosen the former, 
as did the blackbird-, doves, and some other species; but for some 
reason best known to itself it -elected fruit. How much the char- 
acter of the food had to do with the bird's choice it is impossible to 
say, but it is probable that attendant conditions greatly influenced 
the result. Grain is grown on large, open areas, with few or no 
tree- to afford nesting sites, while orchard- oiler every inducement 
to linnets as a permanent residence. Moreover, much of the fruit- 
growing section of the State is divided into small holding-, each with 
a dwelling with accompanying barn-, -bed-, and other building- that 
afford ideal homes for these bird-. Having thus chosen the orchard 

North American Fauna No. 7. r. s. Dept of Agric, p. 80, 1893. 



Buil 30, Biological Survey, U. S. Dept of Agriculture. 



Plate II. 



'& 



<2i 



^ 

& 



Fig. I. 




§ 






Fig. 1. 






fig. 



Fig. 





i 






// 1 






Pig. 7. 




Fig. R. 











Fig. 9. 



Seeds of Common Weeds Eaten by the Linnet. 

Fig. L— Napa thistle Centaurea melitensis). Fig. 2.— Black mustard Brassica nigra). 
Fig. 3.— Alfilaria [Erodium cicutarium). Fig. I.— Knotweed ( Polygonum <"<'■ 
Fig. 5.— Tarweed Madia satira). Fig. 6.— Burweed Ainsinckia tesselaia I 
Turkey mullen {Eremocarpvs setigei I ig. 8.— Milk thistle (Ifurawa mariniana). 

Fig. 9.— Poison oak Rhus diversiloba). 



EOUSE PINCH. l i 

for its home it was only a matter of course thai the bird should 
select as it- secondary food the Dearest available source of supply, 
namely, fruit. For seeds, which are to be regarded as the linnet's 
natural food, grow about the borders of orchards and by roadsides, 
and hence are readily obtained. 

Although the great bulk of fringilline birds normally subsist 
principally upon seeds, at certain times, notably in the breeding 
season, they eat a considerable quantity of animal food, mostly 
Insects. Moreover, their young while still in the nest are usually 
\\h\ largely, and in some cases entirely, upon insects. Quite the con- 
trary is true of the linnet. The adult- eat only a small percentage 
of animal food, even in the breeding period, and \'cc(\ their nestlings 
no more, perhaps less, than they eat themselves. In this respect the 
linnet is probably unique in it- family. Such animal food as the 
bird doc- eat, however, i- much to its credit. Plant-lice (Aphidse), 
especially the woolly species, constitute a large portion of this part 
of the linnet'- food: caterpillars and a few beetles make up most of 
the remainder. 

It i-. however, a- a -^n\ eater that the linnet stands supreme. 
Over 86 percent of its food for the year consists of weed seed-, and it 
is in this held, if anywhere, that the bird redeems itself from the 
odium of it- other misdemeanors. When the immense number of 
linnet- in California i- taken into consideration, with the added fact 
that each one destroys several hundred seeds daily, most of which are 
potential weeds, it must be conceded that the bird renders a valuable 
service to agriculture, for the sum total of weeds so destroyed is 
enormous. 

FOOD. 

In the laboratory investigation of the food of the linnet 1,206 
stomach- were examined, including 16 of nestlings. All were from 
California, and from point- fairly well distributed over tin 1 State. 
with the exception of the northern quarter. The greater number were 
from the fruit-growing sections, so that the western coast region 
is better represented than the part east of the Coast Ranges. They 
were distributed through the year a- follow-: 



January 

February 

March 

April 

May 

June 

July 



88 

:',:, 

is; 

SO 

71 

K',7 

1 is 



Augusl 
September 
< October 
\..\ ember 
I December 



i is 
123 

I I IS 



Total 1. 206 



!i:;7:i No. 30 01 






18 BIEDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

In the first analysis of the food components the two principal 
elements are found to be: Animal matter, 2.4 a percent; vegetable 
matter, 97.G percent. 

Animal food. — This bring- into strong relief the linnet's sins of 
omission. Living in a country where constant war against noxious 
insects is necessary, the bird takes little or no part in the contest, and 
in return for benefits derived from man renders but slight service in 
this direction. 

The small portion of animal food it takes, however, consists almost 
wholly of insects and a large proportion of it of plant-lice (Aphi- 
didse), which from their small size do not attract the notice of many 
species of birds. They appear, however, to be the favorite animal 
food of the linnet, and it is noticeable that a large percentage of them 
are the woolly species. Many of the birds when killed had their 
beaks smeared with the remains of woolly aphides. As these insects 
are notoriously harmful to many trees and other plants, any bird that 
destroys them is a benefactor. It is to be regretted that the linnet 
should not indulge to a greater extent a taste so well directed. Were 
25 percent of its food made up of woolly aphides the fruit it destroys 
would be well paid for. The other contingent of animal matter 
found in the linnet's stomach consists of small caterpillars and a few 
beetles, chiefly weevils. Most birds that feed on plant-lice eat also 
the ants that are usually in attendance upon them, but the only trace 
of ants or of other Hymenoptera in the stomachs of linnets was one 
ant's jaw. Grasshoppers, the favorite food of so many birds, were 
represented by a mere fragment in one stomach. 

Vi getable food. — The most interesting part of the food of the lin- 
net is the vegetable portion. This naturally falls into three cate- 
gories: Weed seed, which amounts to 86.2 percent of the annual food : 
fruit, 10.5 percent: and other miscellaneous vegetable matter. 0.0 per- 
cent. 

Fruit. — Fruit is represented in stomachs taken in January by a 
mere trace. This was probably of no value, only ungathered fruit or 
perhaps belated olives. In stomachs taken in February no fruit was 
found, but in ensuing months it appear- in small quantities, increas- 
ing irregularly until August, when a maximum of 27.4 percent was 
eaten. In September a trifle Less was taken than in A.ugust, and after 
that the quantity decreases until December, in which month a little 
less than 2 percent was eaten. In March the fruit amounted to 
about 6 percent, a quantity hard to account for except on the suppo- 
sition thai it was waste fruit left over from the previous year. The 

a While percentages are sometimes given in fraction, ii need no1 be assumed 
ili.ii extreme accuracy is intended; such figures must be taken as only an 
approximation t<> the truth. 



BOUSE PINCH. L9 

amounl eaten in this month is somewhal surprising in view of the 
fad thai in A.pril less than 2 percenl was consumed, and it is nol until 
June thai the percentage becomes important. It is possible thai the 
supply of weed seed of the pre> ious year may be exhausted by March, 
when the new crop has no1 ye1 ripened; so waste fruil is taken for 
wanl of something bel ter. 

It is practically impossible to identify particular kinds of fruil in 
a bird's stomach unless characteristic seeds or stones are present. 
These are rarely eaten by the linnet, which seems to prefer orchard 
fruit. Cherries, apricots, peaches, and prunes appear to be the favor- 
ites. This choice arises, no doubt, from the character of its beak 
already described. While thrushes and other ' -oft hilled ' birds pre- 
fer the -mailer kind- commonly known as berries, which can be swal- 
lowed whole, the linnet attacks the Larger kind-, which yield readily 
to its powerful beak. Linnets are particularly fond of small pears, 
like the Seckel, and often attack them e\cn when the}' are hard, a 
fortnighl or more before ripe. If undisturbed they will eat every one 
on a tree, leaving the core attached to dry and bla< ken in the sun. 

A few strawberries and fewer blackberries or raspberries were the 
only cultivated -mall fruits that could he identified in the stomachs 
of linnet-. A number of birds from the southern part of the State 
had fed freely on figs, identified by their seeds. 

If the bird preferred an exclusive diet of fruit, there is no reason 
why it- ta-te should not he gratified during the greater part of the 
year. When cherries are ripe in California linnets need eat nothing 
else. The cherry crop would he ample for all their wants, though 
perhaps not much would he left for marketing. The record, how- 
ever, -how- thai in June, which i- practically cherry month in the 
central pari of the State, less than one-seventh of the linnet's food 
consists of fruit. Apricot- are ripe in many parts of the State 
before the month closes, so that lack of fruit can not he urged a- a 
reason why the bird should subsisl so largely upon weed seed. In 
July apricots, peaches, and eai ly figs are available, hut still the linnet 
eat- them only to the extent of one-fifth of its diet, and even in 
Angn-t and September, the month- of maximum consumption, fruit 
constitutes only a little more than one-fourth of the food. 

Weed seeds. — The greater portion of the linnet"- food, as already 
-tated. consists of the seeds of weeds, the mosl important <>l which 
are those of the Napa thistle, black mustard, Allilaria. knotweed, and 
turkey mullen (see PI. II. figs. 1. 2, 3, 1. 7), the total consumption of 
which for the year i- 86.2 percent. This record is not excelled by 
that of any other bird studied, with the possible exception of the tree 
sparrow (Spizella monticola), whose food, however, consists largely 
of grass seed, much of which i- useful. A- there i- an unaccountable 



20 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

increase in the fruit eaten in March, so there is an unexplained de- 
crease in the consumption of weed seed during that month. With 
that exception, the amount taken in each month decreases in a fairly 
regular series from a maximum of 99.8 percent in January to a mini- 
mum of 64 in August. From this month the quantity of seed in the 
stomachs increases steadily to December, when the record ends with 
97.9 j^ercent. 

It seems probable that such a constant and persistent eater of weed 
seed would also eat considerable grain. Stomach records show that 
wheat was identified in one stomach, oats in three, and something very 
like the skin from kernels of corn in five. In this connection it can 
be said that if the linnet does not eat grain it certainly is not for want 
of opportunity. It is evident then that weed seed is taken by the 
linnet simply because it likes it. 

SUMMARY. 

It is natural to conclude that the food most frequently found in a 
bird's stomach is the kind preferred. Applying this test to the linnet 
we find that of the total 1,206 stomachs examined. 1.133, or 94 percent 
of all, held weed seed, and that 807, or nearly 07 percent of the whole, 
contained no other food. On the other hand, fruit was found in 297 
stomachs, or 24 percent of the whole number, but only 38, or 3 per- 
cent of all, were entirely filled with it. In other words, there were 
only 63 stomachs that did not contain weed seed, Avhile 909 contained 
no fruit. 

The miscellaneous portions of the linnet's vegetable food amount 
to only about nine-tenths of 1 percent of the food of the year, and 
all was found in 28 stomachs. Stamens and other parts of flowers 
were found in 14 stomachs only, which does not indicate that the 
injury to fruit buds by the linnet is serious. One stomach contained 
a small leaf gall. Ten stomachs held matter denominated as rubbish, 
consisting of bits of dead leaves, rotten wood, etc., evidently swal- 
lowed unintentionally with other food. 

From the foregoing it appears that, contrary to the statements and 
beliefs of many, the linnet is not a constant and persistent devourer 
of fruit. Examination of the contents of many stomachs shows that 
fruit is far from being its principal article of diet, and it is probable 
that what i> taken i- eaten for the sake of variety or for the juice. A 
far greater quantity <)\' fruit i- eaten by the cherry bird (Ampelis 
cedrorum) and by the robin (Merula migratoria) , both of which occur 
in Cali forma. 

PROTECTION OF FRUIT FROM LINNETS. 

In the case of both these birds, however, the greater pari of the 
fruit eaten consists of wild species, and this fact suggest- a method 



HOUSE FINCH. 21 

by which the California fruit grower may protect his orchard- Prom 
the attack of the Linnet namely, by planting around orchards shrubs 
and tree- the fruit of which will serve to attract birds away from 
the marketable kind-. There are many fruit-bearing shrubs and 
tree- whose products, while worthless to man. are likely to prove more 
attractive to linnets than -avc the orchard fruits. That linnets will 
eat wild fruit appear- from the fact that elderberries (Sambucus) 
were found in ID stomachs, and their apparent partiality for culti- 
vated fruit- is readily explained by the fact thai usually they are 
the only kind- obtainable. 

FOOD ol' YOUNG LINNETS. 

Of the L,206 stomachs of linnets included in this investigation, 40 
were those of young birds taken from the nest. The young vary in 
age from birds 2 days old to those nearly ready to fly. In order to - 
ascertain the exact difference, if any. between the food of the nes- 
tlings and that of the adults, the contents of these 16 stomachs were 
tabulated by themselves and the percentages of the various items of 
food calculated. The results >how 2.4 percent of animal food to 
97.6 of vegetable. The animal food consists mostly of the larva 1 of 
a minute hectic which lives on decayed fruit, with a few plant-lice 
and one -mall fragment of a grasshopper, the only one found in any 
of the stomachs. The vegetable food consists entirely of weed seed, 
the most important of which are the following: Sunflower, bur w T eed, 
milk thistle, and poison oak. (See PL II, figs. 6, 8, 9.) 

No fact connected with the food habits of the linnet is more sur- 
prising than this. The great body of the fringilline birds, though 
subsisting largely and in most cases almost entirely upon vegetable 
food in adult life, feed their young in the early stage of existence 
almost exclusively upon insects or other animal food, and begin to 
give them vegetable food only when nearly ready to leave the nest. 
It isdoubtful if there is an exception to this rule so pronounced as the 
I linnet. A- calculated, the nestlings ate actually less animal food than 
their parent-, hut the difference is so small that it may he accidental. 

r< ONOMIC PLACE OF THE LINNET. 

Admitting, as we must, that the orchardist has just ground- of 
complaint against the linnet on account of depredations upon fruit, 
the bird's claim to favorable consideration must rest upon it- valuable 
services a- a consumer of weed seed and upon it- esthetic value. It 
i- trim and pretty, ha- a sweet song, and in many way- i- a pleasing 
adjunct of rural life- -in fact, many Californians believe that the 
linnet, in spite of it> sin- of commission and omission, should he 



22 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

protected. That the complete extermination of the species, even if 
possible, is not desirable will be readily allowed, but that a reduction 
of its present numbers would be for the general welfare can not rea- 
sonably be denied. Were it possible to destroy half the linnets in the 
fruit-growing sections of the State, there is no doubt that most of the 
complaints against the species would cease. As it is. the fruit grower 
must protect himself by such devices as are suggested by local con- 
ditions, and bear in mind that, while as an individual he may suffer, 
the bird, on the whole, is doing the State good service. 

LIST OF SEEDS FOUND IN STOMACHS OF LINNETS. 

Following is a list of identified seeds, with the number of stomachs 
in which each kind was found. The same kinds of seed< were of 
course contained in many more stomachs, but were so finely ground 
up as to be unidentifiable. It is not unlikely that in identifying the 
seeds specifically errors have been made, but it is believed that few. 
if any, of the generic identifications are erroneous. A few seeds 
were found which have not yet been identified. 

Sedge {Carer sp.) 21 

Sorrel (Rume.r acetosella) 3 

Knotweed (Polygonum aviculare). (PI. II, fig. 4) 128 

Catchfly (Silene sp.) 1 51 

Chickweed (Stellaria media) 1 21 

Spurry i Spergula arvensis > 14 

Amaranth (Amarantus retroflexus et al.) 108 

Calandrinia i Calandrinia menziesi) - 

Miner's lettuce I \lontia perfpliata) : 11 

Wild turnip (Brassica campestris) 13 

Black mustard (Brassica nigra). (Pi. II. fig. 2) 83 

Wild radish ( I?<i/>Ihih us sativum) 108 

Geranium (Geranium dissectum ) 

Alfilaria i Erodium moschatum ) [ 

Alfilaria (Erodium <-i<-iil<iriuin ) . (PI. II. fig. .")» J 

Yellow sorrel (Oxalis corniculata) : 1 

Turkey mullen (Eremocarpus setigerus). (PI. II. fig. 7> 117 

Poison oak (Rhus diversiloba). (PI. II. fig. 9)_ l 

Burweed (Amsinckia tesselata). (PI. [I, ii^ r . <*>> 

Nightshade (Solatium nigrum) 1 

Western ragweed l Vmorosia psilostachya) 

Sunflower (Helianthus sp.) 5 

Mayweed < Inthemis cotula) I 

Groundsel (Senecio vulgaris) 21 

Lesser tarweed (Deinandra fasciculata) l 

Tarweed I Madia sativa). (PI. 1 1. ti~. 5) 5 

Milk thistle i \Iariana mariniana). (PI. II, ii~ r . s > 

Napa thistle (Centaurea melitensis). (PI. n. fig. i» ,;(l 



WESTERN TANAGER. 



23 



The foUowing table -how- the percentages of the various items of 
lotx I of the 1 1 nnel l'< »r each month of i he yea r : 

Table of percentagy ■>■ f ood o) tin linnet for each month in year. 



M..nth. 



January. .. 
February . 

March 

April 

May 

.I'm.' 

Julj 

august 

September 
October . .. 
November 
December. 



I 
average. 



Number of 
stomachs 
examined. 



L86 

• 

71 
L67 
148 
L18 
L23 
L08 



1,206 



Animal 



/*/ m nt. 
0.0 

2. '.' 

l.(i 

8 

6. :; 

7!l 
0. l 
0.0 
0.0 
0.0 



ble I I eaten. 



Weed 



/'-, 



cent. 

'.'7. I 

-1 6 

64.0 
71.6 

91.7 



MN.-.-l TOtal 

lanTo'i. stable 



Percent. 
0.2 

0.0 

1.7 

1.8 

13. i 

I 'A 7 

27. I 
26. 7 
15. 6 

- 

L.8 



0.0 

0.0 
0.0 
L.2 
L.5 
L.5 
L.6 
0.9 
0.0 
0. I 






10. 1 



1 1. 



Percent. 
I 0.0 

97. i 

94.2 

96. 1 

•.'7. - 

99. '.' 
LOO.O 
100.0 
LOO.O 



97. 5 



WESTERN TANAGER. 

t /'// anga ludoviciana.) 

The western tanager, like the robin, occasionally becomes a nuisance 
in the orchard. Ii breeds in the mountainous regions of California 
and nor 
sect ions. 



md northward, and as a rule is not common in the fruit-growing 



DAMAGE TO CHERRY CROP. 



There arc however, tiriies during migration when it fairly swarms 
in some of the fruit-raising regions, and unfortunately this sometimes 
happens just at the time when the cherry crop i- ripening. The bird 
is a late breeder and doc- not seem to care to gei to its nesting ground 
before the last of June or early July. It is thus enabled to begin in 
the southern part of the State when cherries are ripening there, and 
leisurely follow the ripening fruit northward. The year 1896 wit- 
nessed an incursion of these tanagers, when they -wanned over much 
of the State and destroyed a large part of the cherry crop. 

Probably the best account of this occurrence is that of \V. ( ). Emer- 
son (published in the Condor, Vol. V, 1903, p. 64). Mr. Emerson 
says : 

One of t ho most wonderful i ccurrences of the movements of birds in the sea- 
son "i" migration which ever came under my notice, took place at Hayward 
during May, 1896, when countless numbers of Piranga ludoviciana, or Louisiana 

tanagers, began t ake their appearance between May 12 and 14. F'rom the 

18th to the 22d they were to be seen in endless numbers, moving off through the 
hills and canyons to their summer breeding range in the mountains. This con- 
tinued till the 28th, and by .tunc i only here and there a straggling member of 



24 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

the flock was to be seen. They were first found feeding' on early cherries, in 
an orchard situated along the steep hank of a creek, on the edge of rolling hills, 
well covered with a thick growth of live oaks, which faced the orchard on the 
cast. To this thick cover they would fly. after filling themselves with cherries, 
and rest till it was time to eat again. This they would keep up from daylight 
to dark, coining and going singly all day. without any noise whatever being heard. 

Two men were kept busy shooting them as fast as they came into the trees 
which lay on the side next to the oak-covered hills. * * * After the first 
week. I found on going here (May 17), that dozens on dozens of the birds were 
lying about. * * Tanagers lay about everywhere, and no doubt many must 

have flown off to die in the bushes or on the hillsides. * * * I noticed one 
fact of the restriction of the tanagers to the orchards along the hill edges. None 
were found, so to speak, in the larger orchards abouc the town of Hay ward. 
* * Mr. II. A. Gaylord. of Pasadena, Cal., in a letter under date of June 16, 

1S0G, states that " they were seen singly from April 23 to May 1. From this 
date up to May 5 their numbers were greatly increased, and by May 5 there was 
an unusually large number of them. Then for about ten days, until May 10, 
the great wave of migration was at its height. Tanagers were seen everywhere, 
and noticed by everyone. After May 20 they decreased in numbers, and by 
May 20 the last ones had left the valley." * * * He also says : " The damage 
done to cherries in one orchard was so great that the sales of the fruit which 
was left, did not balance the bills for poison and ammunition. The tanagers 
lay all over the orchard, and were, so to speak, 'corded up' by hundreds under 
the trees." 

There must have been thousands of tanagers destroyed all through the path 
of their movement along the State, as they worked their way to the breeding 
grounds. 

Here are two accounts of this great flight of tanagers — one from 
Pasadena, the other from Hayward, 330 miles farther north as the 
bird flies. The time taken by the tanagers in traversing this dis- 
tance was only eight days, so it would appear that individual birds 
did not spend much time in the same orchard. Such sporadic flights 
are hard to account for. The tanagers are in California every year. 
and every year they migrate to their nesting grounds in spring and 
return in fall, but only at long intervals do they -warm in such 
prodigious numbers. Evidently the migration ordinarily take- place 
along the mountains where the birds are not noticed. It is possible 
thai in some years the mountain region lacks the requisite food, and 
so the migrating birds are obliged to descend into the valleys. This 
would seem to be the mosl plausible explanation of the occurrence — 
thai is, thai the usual Line of migration is along the Sierra Nevada, 
but -nine yen 1 -, owing to scarcity of food, or other cause, the flight 
i- forced farther wesl into the Coasl Ranges, where the birds find 
the ripening cherries. The damage done by this species, however, 
i- not confined exclusively to the rare occasions when they appear in 
such extraordinary numbers. R. II. Carr, of Redlands, southern 
( 'ali fornia, wrote us in June. L899 : 

W'iiliMui examining any stomachs it is easy to reporl the value of the Louisi- 
ana tanager to the fruil growers near here, in the city they seem to keep 



WESTERN tan \<;ki;. 25 

almost entirely on the Grevillea trees, sipping the sweel liquid thai exudes 
from tiic blossoms. Bu1 the Andrews Brothers, whose cherry and apple ranch 
is in the upper STueaipe Valley, reporl thai the tanagers destroyed aboul $4,000 
worth of cherries, being almosl the entire crop. Thej used powder and shol 
liberally, bu1 did no1 save I he crop. 

It is to be regretted thai some of the stomachs of these tanagers 
were not saved, in order thai the diet of the species mighl be ascer- 
tained with precision. The only material available for examination 
consists of 16 stomachs Prom various parts of the State, during the six 
months from April to September, inclusive. This number is entirely 
too -mall to afford positive data as to the regular food habits of the 
bird, hut undoubtedly points in the right direction. Although the 
testimony of field observers show- that this tanager cats a good deal 
of fruit, analysis of the stomach contents proves that over 82 percent 
of the food for the six month- indicated above consists of insects, and 
the remainder, nearly L8 percent, of fruit, with a mere trace of seeds of 
a coni fer. 

Insect food. — The largesl item of the animal food is Hymenoptera, 
most of which are wasps, with some ants. Altogether they amount to 
56 percent of the food for the six months, and in August they reach 
75 percent. (They reach 92 percent in April, but only one stomach 
was taken in thai month, so the record is not reliable.) Hemiptera 
stand next in importance, with 8 percent. They are mostly stink- 
bugs, with a lew cicadas. Beetles amount to 12 percent of the food, 
of which less than 1 percent are useful Carabidse. The remainder 
are mostly click-beetles (Elateridse) and the metallic wood -borers 
(Buprestidse), two very harmful families. The former in the larval 
stage are commonly known as wireworms, and bore into and destroy 
or badly injure many plant-. The Buprestids, while in the larval 
stage, are wood-borers of the worst description. Grasshoppers were 
eaten to the amount of \ percent, and caterpillars to the extent of less 
than -_ ; percent. 

Fruit. — The greater part of the fruit eaten appeared to be the pulp 
of some large kind like peaches or apricot-. One stomach contained 
seeds of elderberries; another the seeds and stems of mulberries, and 
two the seeds of raspberries or blackberries. Nearly all these 
stomach- were collected in the mountains, away from extensive 
orchard-, but still the birds had obtained some fruit, probably 
cultivated. 

-I M M VRY. 

It is evident from the testimony that great damage from this 
species occui's only at rare intervals and during the spring migration. 
The greatest lo-ses occurred in May. 1896, when the damage to the 
cherry crop in certain localities was most disastrous. A-. under ordi- 
nary circumstances, the greater part of the food of this bird consists 



26 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. . 

of insects, many of them harmful, the tanager has a fair claim to con- 
sideration at the hands of the farmer and even of the orchardist. 

It is probable that means may be found to prevent, at least in part, 
the occasional ravages of the tanager on the cherry crop. The tan- 
ager, like the robin, prefers to swallow fruit whole, and as the latter 
takes small wild cherries in preference to the larger, cultivated kinds 
when both are equally accessible, it is probable that the tanager would 
do the same; and it is suggested that a number of wild cherry trees 
planted around California orchards might prove an economical in- 
vestment for the orchardist. 

SWALLOWS. 

Swallows are the light cavalry of the avian army — always on the 
move, always on the skirmish line, ever gathering stragglers from 
the insect camps. They furnish another instance, and perhaps the 
most remarkable one, of change of habit induced by civilization. In 
eastern United States the bank swallow and the rough-wing are the 
only species that adhere persistently to their original nesting site-. 
In the West a third species may be added to these, the violet-green 
swallow; but there all the swallows are somewhat less domestic than 
in the East. It is probable, also, that some species, notably the barn 
swallow, are more abundant than when- the country was unsettled, 
owing to the increased number of nesting sites. Supposing for a 
moment that the country was swept bare of buildings, where could all 
the barn swallows find suitable places to nest ( The cliff swallows 
might discover enough overhanging dill's upon which to attach their 
mud domiciles; the white-bellied and the martin, as formerly, might 
not in the hollows of trees, but there are not caves enough east of 
the Mississippi River to afford nesting place- for one-tenth of the 
barn swallows. In the far AYest they would fare better. When the 
country was Grsl settled, barn swallows must have been confined to a 
few rocky cliffs and caves here and there along the seashore or in 
mountain-. Now they live wherever man has erected a structure of 
any kind. 

As is to be inferred from the movements of these birds, their food, 
with some curious exceptions, consists principally of Insects caught 
in mid-air. For this reason all the species are migratory, except in 
the Tropics, for the food supply fails in regions where frosts prevail. 
A- many insects that usually do not fly, periodically 'swarm,' they 
are often captured by -wallow- at such time- in great number-. Such 
is the ea-e with ant- and -white ant-* (Termitidae), which most of 
the lime are concealed in the earth or in log-, hut at certain times 
1 swarm ' in immense numbers. .Many species of hectic- that live in 
offal and ordinarily are not accessible to birds, in case of failure ol 



SWALLOWS. 2i 

food, migrate in great numbers, and then are preyed upon by swal 
lows, flycatchers, and other birds. The destructive cotton boll weevil 
is more or If-- active during the late summer and early fall months, 
and it has been learned thai the -wallow-, as they pa— through the 
cotton State- on their way to their southern winter quarters, catch 
great numbers of them on the wing and so perform an exceedingly 
important service. Engraver beetles (Scolytidse) have frequently 
been found in the stomachs of -wallow-. These insects live under 
bark, and generally are inaccessible to birds, except woodpeckers; 
periodically they migrate from the tree where hatched and matured 
to search for fresh pastures; at such times they are unprotected and 
fall easy prey to any fly-catching bird. Swallow- are peculiarly 
adapted to capturing small insects in mid-air. While their hills are 
weak their month- are wide, and their long wings enable them to fly 
swiftly and turn quickly, SO that they -weep hack and forth through 
a -warm of insects and gather them by hundreds. 

Seven species of swallows, with several subspecies, are commonly 
found within the limit.- of the United State-. Their food habits 
vary hut little. All seven species occur in California, and this num- 
ber include- one. the violet-green, that docs not occur in the East. 

Besides the -wallow- whose food will be discussed in detail in the 
following pages, a few stomachs of the tree -wallow (Iridoprocne 
bicolor), the western martin (Progne subis hesperia), and the bank 
swallow (Riparia riparia) have been examined, but the number is 
entirely too small to be used a- a basis for general conclusions were 
it not for the fad that their contents agree in all essential points 
with those of the other -wallow-, of which a greater number were 
available for examination. In fact, it may be said of all the members 
of the -wallow family that they subsist upon practically the same 
kind of food, with slight variation from month to month. It may 
be laid down a- a general rule that the food of all American swal- 
low- i- derived from the following order- of insects: Coleoptera, 
FTymenoptera, ETemiptera, and Diptera, with a lew individuals from 
one or two other orders, and an occasional spider. So far a- present 
investigation ha- shown, 90 percent <>!' their animal food i- from the 
foiii 1 order- named above, but the relative proportion of each varies 
somewhat with the different species and seasons. With one notable 

exception" the -wallow- take SO little vegetable food that it may be 

passed by a- a negligible quantity, and much even of the little eaten 
is probably swallowed accidentally. 

After the above statements in relation to the food of the -wallow-. 

it i- perhaps unnecessary to dwell upon the great value of these birds 

« The tree swallow of the East (Iridoprocm bicolor) during its southern 
migration freely eats the berries of the bay-berry i Uyrica carolinensis) . 



v 28 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

as insect destroyer.-. They do not consume any product of hus- 
bandry, and the worst that can be said of them is that they eat some 
useful insects with the harmful ones, though the former are in a 
very decided minority. This statement, however, applies to any and 
all insect-eating birds. It would be just as reasonable to expect a 
mower or reaper to cut grain and leaye the weeds standing as to sup- 
pose that from the hordes of insects around us birds will select only 
the ones that are injurious to man and leaye untouched those that are 
beneficial. Then, too, a superabundance of any species of insects, 
eyen beneficial ones, would be a nuisance. The service which swal- 
lows render is to prey upon the whole insect tribe and so to reduce 
the flood of insect life to a lower leyel where it may be more easily 
dealt with by man. 

CLIFF SWALLOW. 

(Pctroclielirion lunifronk.) 

In the Eastern States the cliff swallow has practically abandoned 
its original nesting sites under cliffs, and now nests under the eaves 
of houses and other buildings. The writer has counted 80 nests 
beneath the eaves of 1 barn. In California the bird has taken up 
with the new order of things to some extent, but has not entirely 
abandoned its old habits. It is a migrant and remains in the State 
for about six months only during the breeding season, 'which is the 
time when the bird does the most good. 

The following discussion of the food of the cliff swallow is based 
upon the examination of 123 stomachs, representing every month 
from April to September, inclusive. 

Vegetable food. — Vegetable food to the extent of 0.32 of 1 percent 
was found. In most cases this was simply rubbish taken acciden- 
tally, though it includes a few small seed-. 

Annual food. — Of the animal matter the largest item is Hymenop- 
tera. These insects formed over 30 percent of the total food: most 
of them were bee- and wasps, and small parasitic species were identi- 
fied in a number of stomachs: a few were ant-. Unfortunately, 
many parasitic insects are eaten by birds that take their prey upon 
the wing, such as swallows and flycatchers. The fact is to be 
deplored, but in mosl cases the percentage is not large. Perhaps the 
most interesting insect among Hymenoptera eaten i- the common 
honey-bee (Apis mellifera). Of these. 31 were identified, all con- 
tained in 11 stomachs, in one of which were 8 individuals. All were 
drones — that i-. male-. Not a trace of a worker bee was found. In 
two stomachs drones constituted the whole food and in several others 
the principal part. It is probable that most of them were taken 
when the queen made her marriage (light. So far as the writer has 



SWALLOWS. 29 

been informed, bee keepers do not regard tho destruction of drones as 
injurious to the swarm. In most cases drones arc superabundant 
and instead of contributing to the food supply they are a drain upon 
it. so thai the destruction of some of the surplus males is a positive 
benefit to the colony. 

Hemiptera, or bugs, stand next to Hymenoptera in importance in 
the food of the cliff swallow. They form a little less than 27 percent 
of the whole diet, and arc represented by eight families, namely. 
assassin-bugs, leaf-bugs, squash-bug family, stink-bugs, shield-bugs, 
tree-hoppers, leaf-hoppers, and jumping plant-lice. fl All of these, 
excepting the assassin-bugs, are injurious to plants, and some of them 
are pests at all times. Of these, probably the leaf-hoppers (Jassidae) 
are the worst. They suck the juice- of plants, particularly grasses, 
which they infest by millions. They arc said to have but few enemies, 
of which birds are the most effective. It is probable that they are 
captured by swallows when just skimming over the surface of fields, 
or are snatched from the top- of grass and weeds. They were found 
in 27 stomachs. 

Leaf-bugs (Capsidse) arc a very large family of harmful insect-, 
which feed almost entirely upon plants. Some species of this family 
arc pests of the worst description. Leaf-bugs were contained in 48 
stomachs. The other insects of this order are more or less harmful, 
but were not eaten so extensively. 

Beetles of all kind- aggregate a little less than 19 percent. Of 
these, 2 percent were usefu] species, such as carabids and coccinellids. 
The other- belong to 12 different families, most of which are harmful, 
some wry much so. Among them were a number of aquatic species. 
These were probably captured by the swallows when Hying just above 
the surface of the water. The principal flights of beetles do not 
occin- during the day. but chiefly in early evening and at night. 

Flies are eaten, by dill' -wallow- to the extent of nearly 12 percent 
of the food. Most of these are the species commonly known as 
gnat-, but one stomach contained a large horsefly (Tabanidse). The 
gnat- have a habit of -warming afternoon- and evenings, when many 
arc probably snapped up by -wallow-. 

The remains of dragon-flies, lace-winged flies, ephemerids, and 
spiders make up the rest of the food, of a little more than :; percent. 
A- spiders do not fly, it may be asked how they were captured by 
the -wallow-. They probably were snatched from their web- or from 
the tops of weeds a- the bird- passed. Swallow- pick up -ub-tance- 
even from the ground, as i- shown by the vegetable component of 
their food, and by other fact- to be given presently. 

a Plant-lice and scale-insects were not present, and this may he explained from 
the fact that their lives are passed mostly in a wingless condition. 



30 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

FOOD OF YOUNG. 

Among the stomachs examined were those of 22 nestlings, varying 
in age from '2 days to those just ready to leave the nest. They were 
taken from May 30 to July 2, inclusive. In order to ascertain if im- 
portant differences exist between the food of the adults and that of the 
young, the contents of these stomachs were tabulated separately. 
Comparison shows little or no difference in the quantity of vegetable 
matter eaten by adults and young. 

The animal matter in the food of the young is precisely of the 
same kind as eaten by adults, but the proportions are rather differ- 
ent. Hymenoptera are the largest item in the food of the young 
as well as of the parent birds, and amount to 42 percent for 
the former against 39 percent for the latter. Diptera stand next in 
importance, with 30 percent for the voting against 12 percent for the 
adults. As these insects are mostly soft-bodied, it is the usual custom 
of birds to feed a greater proportion of them to the young. Hemip- 
tera amount to a little more than 10 percent of the nestlings* food, 
while the adults eat them to the extent of nearly 27 percent. Beetles 
are fed to the young to the amount of about 10 percent, while the 
parents eat them to the extent of 19 percent. This again might 
naturally be expected, as most beetles are hard and les- easily 
digested than flies and some other insects, and hence are less suitable 
food for young birds. 

From the foregoing it is evident that the food of young cliff 
-wallows does not differ in kind from that of the adults, but is dis- 
tributed among the various orders of insects in somewhat different 
proportions. Hymenoptera and Diptera constitute nearly three- 
fourths of the diet, evidently because they are soft and easily broken 
up and digested. Beetles and bugs appear in the stomachs less 
frequently. While beetle- are not extensively eaten, it is worthy of 
note that the variety is considerable, as representatives of no fewer 
than 1<> species were contained in the stomach of one nestling. One 
stomach held a few hit- of eggshell, and gravel was identified in 
two other-. One of these contained 7 good sized gravel -tone-: the 
other, pieces of glass and gravel. The supposed function of gravel 
in the stomachs of birds is to assist in breaking up the food. That 
gravel should l>c given young cliff -wallows when not taken by the 
adult- i- remarkable. The feeding of gravel to the young ha- been 
noted in the case of other species of -wallow-. 

WESTERN BARN SWALLOW. 

i ii hnii'hi < rythrogastra. i 

The barn -wallow is rapidly learning, not only that the structures 

huilt by man afford excellent nesting sites, hut that the presence of 



SWALLOWS. .", 1 

man is a sufficient protection against enemies. This species is gen 
erally distributed over the west coast region, but it is not so common 
as it is in the Bast, probably because of the relative scarcity of nest 
ing sites. Ii is not improbable, however, that the end of the present 
half century will see the barn -wallow as common throughout the 
wlmlc of t lie region as it is in the Bast. 

Eighty-two stomachs of barn -wallow- were examined, taken Prom 
April to October, inclusive, though April was represented by only 
two stomachs and October by one. While a greater number would 
have been desirable, the close resemblance of the food to that of 
the eastern birds, as shown by the contents of these stomachs, gives 
assurance that the results are reasonably reliable. 

Vegetable food. Practically no vegetable food was found in the 
stomachs examined. A single unknown -red was contained in a stom- 
ach taken in September. 

Insect food. — So far as these 82 stomachs show, the western barn 
-wallow subsists entirely upon insects, and it may be added that the 
same is true of the eastern bird. 

The largest item of food i- made up of Hemiptera of various 
families, amounting to nearly 39 percent of the whole. None of t hese 
insects was present in the two stomachs taken in April, but in every 
other month they constitute a large percentage of the stomach con- 
tent-, and in September, when 38 stomachs were taken, they amount 
to 90 percent of the food for that month. Representatives of 8 fami- 
lies were identified, but the principal and most important one- are 
the leaf-bugs (Capsidse), which were found in 44 stomachs. 

Flies are next in importance, and amount to 32 percent of the food. 
Most of them belong to the family of the common house fly (Mus- 
cidse), though probably there were other- too badly mangled to be 
identified. Xo lon<r-le<r<red crane-flic- (Tipulidse) , usually commonly 
eaten by birds, were found. 

Hymenoptera constitute I s percent of the food. Most of them 
consist of wasps and wild bees, hut a few stomach- contained ants. 
One stomach had a drone boney-be*e. Several birds had eaten para- 
sitic species of Hymenoptera; a separate account was kept of these 
so far as possible, but the total amount summed up to only about one- 
fourth of 1 percent of the whole food. 

Beetles affgre&ate nearlv 10 percent of the whole, and belong to 13 
families, with no preference for any. The bird probably snatches 
any and all beetles which it comes across. A few of the destructive 
engraver beetles (Scolytidae) were found in 3 stomachs. Dragon- 
flies and several unidentified remain- constitute the remainder of the 
food and amount to a little more than 1 percent. 



32 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

FOOD OF YOUNG. 

The stomachs of two broods of nestlings of 4 each are included in 
the foregoing. The contents do not differ from those of adults ex- 
cept that they include a small percentage of gravel. Some of them 
contained also fragments of eggshell; one had a piece of mother-of- 
pearl (nacre), and one a small splinter of bone. It is curious that 
these indigestible substances should be so often fed to nestlings when 
the parent birds seldom take them. 

VIOLET-GREEN SWALLOW. 

(Tachydneta thalassina l<i>i<lu.) 

The violet-green swallow does not occur east of the Great Plains. 
Its general habits appear to be almost identical with those of its east- 
ern relative, the white-bellied swallow. 

The natural nesting site of both species was a hollow in a tree, and 
the western bird still adheres to the original habit and nests in the 
hollows of oaks and other trees, bttt the white-belly has to a great ex- 
tent followed the example of so many of its relatives, and has taken 
to holes in buildings or to boxes put up for avian use. 

In its food habits the violet-green exhibits no marked peculiarities; 
in fact it may be said that the food of the different species of swal- 
lows differs in degree rather than in kind. Stomachs of the violet- 
green have been collected in every month, except June, from March to 
September, inclusive, but only 7 were taken earlier than July. In 
that month, however, and the two following months 67 were obtained, 
a sufficient number to give a fair idea of the food at this season. 

Insect food. — Insects constituted practically the entire contents of 
these stomachs. No spiders were found, and the only vegetable mat- 
ter was a single seed, no doubt accidental. 

As with the barn swallow, the largest item is Hemiptera, or bugs. 
These are represented by 1<) different families, of which the leaf- 
hoppers (Jassidae) were the most numerous, and the Leaf-bugs (Cap- 
sidae) next. Altogether they amount to 36 percent of the food. 

Diptera -laud next in importance, and in 1 1 1 i ^ respect also the violet- 
green resembles the barn swallow. They constitute nearly 29 percent 
of l he food. Neither Diptera nor Hemiptera. however, are eaten 
as freely by the violet-green as by the barn swallow, and the defi- 
ciency LS made up by I Iyinenoplera. 

Hymenoptera amount to 23 percent of the food, and in the 
month of July were mostly made up of ant-. Six stomachs taken 
on the same day and in the same locality were entirely filled with 
these insects. One taken at the same place on the following day 
was half Idled with them, and this, with the exception of 1 percent 



CALIFORNIA SHRIKE. 33 

contained in one stomach in Angn-t. is the whole story of ants in 
the food of ilif violet-green. All of the other hymenopterous food 
consists of wasps and wild bees. In explanation of the fad thai 
this bird eats ants freely for ;i short time and then eats no more, 
ii may be stated that much of the time they are not obtainable. 
It i- only when the insects arc on the wing while swarming that (he 
swallows can catch them, and then, being very numerous, they are 
eaten freely. 

Beetles collectively amount to something over 11 percent of the 
food of the violet-green. Of these nearly 3 percent are Carabidse, 
with a few coeciiiel 1 ids and carrion beetles, which must be reckoned 
a> useful insects. The rest, over s percent, are of several families. 
all of which are more or less harmful. Three stomachs, collected 
at the same time in Carmel Valley, are of interest. They contained 
respectively T2. 45, and 40 percent of scolytid or engraver-beetles. 
This was in the region of the Monterey pine (Pinus radiata), and 
then- is no doubt that these insects prey upon those trees, and 
probably were taken when migrating in a swarm to fresh foraging 
grounds. A few moths, with some unidentified insects, make up 
the remainder of the animal food, a little more than 1 percent. 

CALIFORNIA SHRIKE. 
(Lanius ludovidanus gambeli.) 

The California shrike is common in parts of the Pacific coast 
region. At the present time fence posts and telegraph lines are the 
vantage point- from which shrikes ordinarily scan the ground for 
prey, and in certain parts of the valley region it is unusual to glance 
along a line of wire and not see one or more within a short distance- 
It does not seem that trees and shrubs could ever have adequately 
supplied the need for lookout stations which is now filled by the poles 
and wire-. 

There seems to he a mysterious sympathy between the shrike and 
the little sparrow hawk, or perhaps their relations are inspired by 
jealousy. The sparrow hawk also occupies the pole- and wires as a 
lookout for prey, and whenever a hawk' stations himself upon one of 
the pole-, there, at no great distance, is sure to he a shrike keeping 
close watch upon the movements of the larger bird. When the latter 
moves the shrike follow-, and seems to aim to keep the other continu- 
ally in view. Perhaps the shrike sees in the hawk a rival and con- 
siders that his preserves are being trespassed upon, though one would 
think' there was room enough and prey enough for both. No case of 
actual conflict between the two ha- been observed only this constant 
and unremitting surveillance on the part of the shrike. 
9379 — No. 30—07 3 



84 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

The shrike resembles a bird of prey in form of beak and. to a cer- 
tain extent, in food habits. Unlike the true birds of prey, however, its 
feet are not provided with talons for seizing prey and holding it 
securely while it is being torn into pieces. Whenever the shrike cap- 
tures game that must be torn apart it presses it firmly down into a 
forked branch where it can readily be dissected. 

The habit of the shrike of storing food apparently for future con- 
sumption has often been noticed. When food is abundant surplus 
captures are hung on thorns, sharp twigs, or. in recent times, the 
barbs of wire fences until needed ; but as such occasions seldom arise, 
nine-tenths of this stored food is wasted so far as the shrike is 
concerned. Various more or less plausible explanations of this 
habit have been offered, but the simplest and most natural seems to 
be that much of the time the bird hunts simply for the pleasure and 
excitement of the chase, and as prey is often captured when hunger 
has already been satisfied it is stored for future use. It is the same 
instinct and lust for slaughter that prompts man to kill game that 
he can not use. The habit seems to be manifested also in a somewhat 
different way by the crow and magpie, which store up bits of glass 
or bright metal for which they can have no possible use. In the 
case of the shrike, however, the habit is useful to man if not to 
the bird, for most of its prey consists of noxious creatures, the de- 
struction of which is a decided benefit. 

The diet of the shrike and that of the sparrow hawk are almost 
exactly alike. It is a curious illustration of two species standing 
far apart systematically but by special modification approaching 
each other in food habits. The sparrow hawk has all the equipment 
of a carnivorous bird, but owing to its diminutive size its attacks- 
are necessarily confined to the smaller kinds of prey, largely insects. 
The shrike, on the other hand, is a member of a group almost 
purely insectivorous, but it is so large and strong and has a beak 
so modified that in addition to its ordinary diet of insects, it is able 
on occasions to capture and tear apart small birds and mammals. 
While at present the two birds subsist upon much the same diet it 
i- evident that their food habits have been modified in different 
way-. The natural food of the hawk family as a whole i> vertebrate 
animals, to which some of its members, including our little sparrow 
hawk, have added a large percentage of insects. The normal food 
of the shrike is insects, to which on occasion- it adds the smaller 
specie^ of vertebrates. 

Like the bird- of prey and some other birds, the shrike habitually 
disgorges the indigestible portion- of its food after the nutritive part 
ha- been digested. The bones ami hair of mice are rolled into com- 
pact p. -Net- iii the stomach and finally disgorged. From examination 
of these a very good idea of the shrike's food may be gamed. 



I ai.iiokma SHRIKE, 35 

A shrike of the eastern subspecies was kepi in confinement for -nine 
week- by the Biological Survey and nolo made in regard to its food 
habits. A thorny bush was placed in the cage, and whenever the 
bird was given food in excess <>f it- immediate wants it impaled the 
surplus upon a thorn, taking great pain- t<> press it securely down. 

On one occasion a dead mouse was placed iii the Cage; it wa- at once 
seized and forced into the fork of the bush and was then torn piece 
meal and eaten. Note was taken of the time when the last hit Was 
swallowed, and a close watch kept for further results. In an hour 
and a half the bones and hair of the mouse were disgorged in the form 
of a neat pellet. Everything digestible had been -tripped from the 
hone-. A May-beetle (Lachnosterna) was eaten and the pellet con- 
taining the remain- appeared in an hour and twenty minute-. At 
another time a ground beetle (Calosoma) and a -link bug (Nezara) 
were eaten and their remain- appeared in forty minute-. A- both 
of the insects are nan-eon-, at least to human smell and taste, it 
i- possible that they may have been unacceptable to the stomach of 
the bird, and so were rejected before digestion was complete. On 
another occasion a second Calosoma and a moth were given, and their 
remain- were regurgitated in an hour and fifteen minute.-. These 
experiment- -how how rapid i- the process of avian digestion. 

In the investigation of the food of the California shrike 124 stom- 
achs were examined. They were collected in every month, but the 
greater number were taken in the warmer months. 

Vegi t<il>l< fo'od. — Animal food of all kinds amounts to 97.5 percent, 
or -o nearly the whole that it is fair to suppose that the greater 
part of the 2.5 percent of vegetable matter present was swallowed 
unintentionally -that i-. when sticking to something else. All of it 
was contained in ( .> stomachs. Fruit appeared in 2 stomachs, seeds in 
2, and rubbish in 6. Of these probably only the fruit was taken as 
food. One stomach was filled with elderberries to the amount of 84 
percent of the content-, the other with the seeds of blackberrie- or 
raspberries to the extent of 13 percent. It thus appear- that the 
shrike sometimes eat- fruit. 

An',,, ml food. — The animal portion of the shrike's food may be 
divided into three part-: [nsects, s "> percent : spiders and a few snails, 
etc., 2 percent: vertebrates, L2 percent. 

Insect food. --In comparing the food of eastern subspecies of 
shrike and the one under discussion, we find that more insects are 
eaten by the western one. Tin figures for the eastern bird are: 
Insects, 68 percent; spiders, I percent; vertebrates, 28 percent. The 
difference i> undoubtedly due to climate, the western bird being 
able to find insects all the year round, while the eastern one discovers 
very few during the winter. Insects probably are always preferred 

when obtainable. 



36 BIKDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

Of insects eaten by the shrike, the largest item is Orthoptera — 
that is, grasshoppers and crickets — which amount to nearly 43 percent 
of the whole food. They are eaten in every month of the year, and 
in August and September reach nearly TO percent. These are the 
normal grasshopper months, the ones in which Eastern birds enjoy 
their annual grasshopper feast. Ordinary grasshoppers form the 
greater part of this item of food, but a good many crickets are eaten, 
especially the brown and striped so-called wood crickets. One group 
of these is particularly noticeable — a group of large soft-bodied mon- 
sters of the genus Stenopelmatus, many of which live under dead 
leaves, stones, and rubbish, and do not often voluntarily show them- 
selves by the light of day. It seems strange that the shrike, a lover 
of open and sunshine, manages to discover these creatures. They are 
sometimes called ' sand-crickets,' and perhaps at times come out into 
the open, but the writer has never seen one except when dug from 
under rubbish. It is not known whether these insects are harmful or 
beneficial, so the shrike's consumption of them has no economic inter- 
est. It is quite the contrary, however, with regard to grasshoppers, 
for they are harmful in all stages of existence, and the shrike is 
directly beneficial to the farmer to the extent that it destroys them. 

Beetles collectively are second in importance in the shrike's diet. 
They amount to 16 percent of the food, but of this about 7 percent 
are the useful ground beetles (Carabida?) and carrion beetles (Sil- 
phidee). The rest are mostly harmful. The presence of these last 
is a curious point in this connection. These insects are probably use- 
ful, and while no great number of them are consumed, it seems rather 
strange that they are eaten at all. The surroundings of these beetles 
are not pleasant, and they do not generally serve as food for birds 
except crows and other garbage hunters. Is it possible that the 
shrike finds them on the game which it has hung on twigs or thorns? 
They were noted in 8 of the 124 stomachs, and three species were iden- 
tified. Most of the beetles eaten by the shrike are of the larger spe- 
cies, but it does not disdain small game, and quite a number of small 
leaf -beetles and weevils were among the others. 

Ants and wasps amount to something more than 11 percent in the 
diet of the shrike. Naturally they are mostly eaten in the warmer 
months, and the wasps far outnumber the ants. 

Moths and caterpillars are taken to the extent of somewhat more 
than 7 percent, and seem to be a regular though small component of 
the food. Unlike the wasps, the greater number of these were eaten 
in the colder months. One stomach was entirely tilled with the re- 
main- of ir> moths, a most unusual occurrence, for adult Lepidoptera 
do not form a large element of the food of any bird yet investigated. 

Bug- and flics are eaten occasionally. The stomachs taken in Feb- 
ruary contained a good percentage of Hemiptera, and so did those 



CALIFORNIA SHRIKE. 87 

collected in July. Tn one stomach remains of robber-flies (Asilidse) 
were detected. This is a family of large predaceous flies, some species 
of which are said to prey upon honey-bees. These two orders and a 
few other odd insects constituted 5 percent of the food. 

Spiders and several other kindred creatures form less than 2 per- 
cent of the food, hut though not eaten in great numbers they appear 
in a good many stomachs. In one stomach was found one of those 
bristly and uncanny monstrosities of the order of jointed spiders 
(Solpugida). It is wonderful that any bird should attack one, still 
more that it should eat it. as it would seem to be about as palatable 
as a paper of pins. The lingual ribbon, or tongue, of a snail Avas 
found in one stomach, and bits of what appeared to be the limbs of 
small crustaceans in several. They did not amount to a noticeable 
percentage. 

Vertebrates. — The vertebrate part of the shrike's food amounts to 
a little more than 12 percent, and consists of the remains of small 
mammals, birds, and lizards. Mammals were found in 4 stomachs, 
birds in 2, and lizards in 12. Neither of the birds could be identified 
further than that both were small song birds. Of the mammals, 
one was a pocket mouse (Perognathus), one a young field mouse 
(Microtus), and one a shrew (Sorex). The fourth mammal could 
not be identified, as there Avas little left except hair. The lizards 
Avere not recognizable either generically or specifically, as the remains 
consisted only of bones and scales. From an economic standpoint, 
lizards are useful animals, as they subsist on insects. The same is 
true of birds, so that in destroying birds and lizards the shrike is 
doing harm. Fortunately, it does not eat many birds. The destruc- 
tion of the mammals is an unmixed blessing, except, perhaps, in the 
case of the shrew (Sorex), AA'hich is largely insectivorous. Even if 
all the above vertebrates Avere useful the score against the shrike 
would not be a very heavy one and would not outweigh the 
value of its services in destroying grasshoppers. In the writer's field 
experience with the shrike only one attempt to capture a vertebrate 
animal was observed. In this case the shrike Avas seen to plunge 
into a thicket of weeds in pursuit of a brood of tiny quail, but a 
feAv seconds later it emerged in a great hurry, closely followed by 
the irate cock quail. As a matter of fact, the noxious mammals 
eaten both by the eastern and western shrikes far outnumber the 
birds, and when to the former are added harmful insects the balance 
is very largely on the credit side. 

food of rouNO. 

Xo nestlings of shrikes were at hand for investigation, but the 
stomachs of tAAo young just out of the nest were examined. Both 



38 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

were filled with beetles. ants, wasps, and crickets. In a bird so 
thoroughly insectivorous as the shrike it is not probable that the food 
of the nestlings differs essentially from that of aduhs. 

As a feature of the landscape and as lending animation to rural 
scenes the shrike in California is a pronounced success, and when one 
sees him jauntily balancing on a telephone wire it is pleasant to 
reflect that in his economic relations he is as admirable as he is from 
the esthetic point of view. 

VIREOS. 

The vireos are a group of rather small tree-haunting birds of plain 
colors, modest habits, and sweet but unobtrusive voices. One or the 
other of the several species inhabits pretty much everything in the 
way of a tree from the monarchs of the forest down to the humblest 
underbrush. In thickly settled country vireos inhabit gardens, 
orchards, and city parks, and shade trees along the village streets. 
Most of them are migrants, and leave the United States in winter, 
but a feAv remain on the Pacific coast throughout the year. Their 
food consists largely of insects, though a little fruit and some seeds 
are occasionally eaten. 

In the insect diet of the vireos there is one element which consti- 
tutes a bar sinister on an otherwise brilliant escutcheon. All the 
species investigated show a decided taste for ladybirds — that is. 
coccinellid beetles. Xo other genus of birds, nor any single species 
(with one possible exception), so far has been known to manifest 
such fondness for these useful insects. In California the destruction 
of ladybird beetles is perhaps a greater crime than it would be in 
almost any other section of the country, for here the bark scales and 
plant-lice upon which these beetles feed are very destructive, and 
every device for their extermination has been employed, even to 
importing several foreign species of these predatory beetles. 

Time was when the devastation of the San Jose scale and several 
other species of scale insects threatened the fruit industry of Cali- 
fornia, and there can be no reasonable doubt that the coccinellid 
beetle- of both the imported and native species were largely instru- 
mental in checking the spread of these pests. It is to lie remarked 
that these beetle- are wonderfully abundant in California, probably 
more SO than any other family. The writer found them upon corn, 
weeds, grass, and bushes, often where apparently there was none 
of their natural food. In mitigation of the vireos' habil of eating 
ladybirds all that can be said is that where there i- such a super- 
abundance of the insects the damage is minimized. 

The writer i- glad to he able t<> add thai besides the coccinellids, 
vireos eat manv harmful insects, among which are the black olive 



vibeos. 39 

scale. Here, then, is an instance where the bird eats the useful beetle 
and also its noxious prey. A.s there is nothing to indicate thai the 
bird exercises a choice between them, we must infer thai it eats both 
whenever ii finds them. It eats the beetles and the food (scales) 

upon which they feed. From this point of view also it must be 

allowed t hat t he harm done by t he vireo- in eat ing coccinellids is oll'-cl 
to some extent. 

W'l'.si i.i:\ w \i;nu \<. \ [REO. 

(I nit, i/Hiii s K?j a instini. I 

One hundred and ten stomachs of the warbling vireo have been 
examined. They were collected during the seven month- from April 
to October, inclusive, and though hardly a- many as could be desired, 
they probably furnish a fair idea of the food during that portion of 
the year. 

Vegetablt font/. — [nsects, with a few spiders, amount to over 97 
percent of the diet, leaving less than -\ percent of vegetable matter, 
practically all of which was taken in August and September; it 
consisted of wild fruit (elderberries), a few seeds of poison oak, a few- 
other seeds, and some rubbish. 

Animal food. — Of the animal food the largest item is Lepidoptera ; 
that is, caterpillars, moths, and the like. These amount to something- 
more than V-\ percent of the whole. Caterpillars make up the great 
bulk of this portion of the food and are a very constant and regular 
article of diet. Fewer are eaten in July and August and more at the 
beginning and end of the season. In April they amount to over 82 
percent of the food of the month. Pupae of codling moths were iden- 
tified in four stomachs, and minute fragments probably of the same 
were found in several others. A few adult moths also were found, 
but the species could not be identified. 

Ilemiptera are the next most important item of diet, and amount 
to 21 percent. They consist of stink-bugs, leaf-bugs, leaf-hoppers, 
spittle-insects, tree-hoppers, and scales. The last were the black olive 
species (Saissetia olea j ). Coccinellid beetle-, or ladybirds, were eaten 
to the extent of over L9 percent of the whole. None was in the 
stomachs taken in October, while the greater part (over 63 percent) 
was contained in those obtained in July. The species belong to the 
genera Ilippodamia and Coccinella, which are larger than those of 

the genus Scymnus -elected by the warbler-. Other beetle-, mostly 
harmful species, amount to more than 7 percent. 

Ilymenoptera, which are an important food of the warbler-, are 
conspicuous by their absence in the stomach of the warbling vireo. A 
little more than 1 percent represents the -um total. They consist of a 
few ants and an occasional wasp. 



40 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

A small number of flies, grasshoppers, and dragon-flies make up a 
little more than 3 percent of the miscellaneous insects. Spiders were 
eaten to somewhat less than 2 percent. 

CASSIN YIREO. 
(Vireo solitarius cassini.) 

This is another of the tree foragers living in summer in orchards, 
canyons, and forests. 

Its food consists of the same elements as that of the last-described 
species, but in somewhat different proportions. Forty-six stomachs 
were examined, taken in every month from April to November. The}' 
afford at least a fair indication of the food for those months. 

Vegetable food. — The vegetable food, which was only a little more 
than 2 percent of the total, was made up of leaf galls, seeds of poison 
oak, and a few bits of rubbish. Not a trace of fruit was found. 

Animal food. — The animal matter amounts to nearly 98 percent of 
the whole. Hemiptera are the largest item and amount to nearly 51 
percent. The various families represented are those of the squash- 
bugs, leaf-bugs, stink-bugs, shield-bugs, leaf-hoppers, tree-hoppers, the 
jumping plant-lice, and scales. The latter are represented as usual by 
the black olive scale, which was contained in four stomachs. Caterpil- 
lars, with a few moths, are next in importance and form more than 
23 percent of the whole food. They were eaten in every month and 
are evidently a favorite diet. 

Hymenoptera are eaten much more largely by this species than by 
the last. They amount to over 7 percent, and are mostly wasps, with 
a few ants. This record, however, is likely to be modified by further 
investigation. 

Ladybird beetles were eaten to the extent of a little less than 6 
percent, which is quite reasonable as compared with the record of the 
warbling vireo. It is, however, much greater than that of any bird 
outside the present genus, except the pygmy nuthatch, and in the 
case of that bird the evidence is too meager to be accepted at its face 
value. Other beetles amount to a little more than 3 percent of the 
food, and are mostly weevils and small leaf-beetles (Chrysomelidae). 
A few flics, grasshoppers, and other insects amount to somewhat more 
than 2 percent, and these, with 4 percent of spiders, make up the 
remainder of the animal food. 

SUMMARY. 

In glancing over this record of the Cassin vireo it appears that 
bugs are the favorite 1 food, as shown by the numbers consumed; but 
caterpillars, though second in quantity, are eaten with greater regu- 



VIBEOS. 41 

larity and appear in the food of ever}' month. The consumption of 
ladybirds is \»t\ moderate for a vireo, and on the whole the bird 
probably does not do much harm in this way. All the other hectics 
are harmful, a> arc most of the other insects which compose the bird's 
food. 

HUTTON VIREO. 

( I m o huttoni. i 

This species is a resident of most parts of California west of the 
great interior valley. In food habits it does not differ remarkably 
from the foregoing, but the various elements of its food are in 
slightly different proportions. 

Vegetable food. — Examination of 54 stomachs shows that less than 
2 percent is composed of miscellaneous articles of vegetable origin. 
One stomach contained a few seeds of elderberries, two contained 
those of poison oak. and these with a few galls and some rubbish 
make up the whole of this part of the food. It would seem that with 
most of the vireos vegetable matter is taken accidentally, or possibly 
experimentally to see how it tastes, rather than as an approved article 
of diet. 

Animal food. — Of the 98 percent of animal food the largest item is 
Hemiptera, as is the case with many of the vireos, titmice, and gnat- 
catchers. These insects amount to 49 percent of the food of the pres- 
ent species, and are represented by the following families: Assassin- 
bugs, leaf-bugs, stink-bugs, leaf-hoppers, tree-hoppers, jumping 
plant-lice, and bark scales. These last consist, as is so often the case, 
of the black scale, which appeared in 8 stomachs. Caterpillars, with 
a few r moths and cocoons, are next in importance, and constitute over 
22 percent of the food. These tw o items not only make up more than 
two-thirds of the diet, but are eaten with great regularity through the 
year and seem to be the staples of the bird's food. 

Beetles, collectively, amount to nearly 11 percent. Of these 8 per- 
cent are ladybird-, somewhat more than were eaten by the Cassin 
vireo. but only half of the amount eaten })y the Sw r ainson vireo. The 
remaining beetle-, less than 3 percent, were largely weevils, among 
which a few engravers (Scolytidse) could be distinguished. Hyme- 
noptera, including both wasps and ants, form about 7 percent of the 
food. Among them severa] parasitic ones were identified, but there 
were not enough to be of any great economic interest. A few mis- 
cellaneous and unidentified insects amount to nearly 5 percent of the 
food. Flies and grasshoppers make up a part of this, but they are 
only rarely eaten. Spiders are consumed regularly but sparingly. 
They amount to a little more than 2 percent. 



42 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

OTHER CALIFORNIA VIEEOS. 

Several other species and subspecies of vireos occur in California, 
but in the general character of their food they agree closely with the 
foregoing. 

BEETLES FOUND IV STOMACHS OF VIREOS. 

Coccinella t. calif ornica. Gastroidea viridula. 

Hippodamia convergent. Blapstinus spp. 

Scymnus spp. ipion cribricollis. 

Agrilns spp. Balaninus spp. 

Crepidodera helxines. Copturodes koebelei. 



WARBLERS. 
(Mniotiltidse.) 

The warblers, or more properly the wood warblers, to distinguish 
them from the warblers of the Old World (Sylviidse), are a large 
family of rather small and often brightly colored birds. For the 
most part they inhabit woods and shrubbery, and while some of them 
obtain their food from the ground they seldom wander far from 
trees and bushes. The species and subspecies are so widely dis- 
tributed that, excepting the deserts, there are no very extensive areas 
within the boundaries of the United States that do not have their 
complement of these interesting birds. Their food consists largely 
of insects, and they subsist upon species which frequent the leaves 
and trunks of trees. Wasps and flies (Hymenoptera and Diptera) 
form a large portion of their diet, and as these insects are the best 
of fliers a considerable portion of them are taken on the wing. The 
warblers probably eat more of these elusive insects than does any other 
family of birds except the flycatchers (Tyrannidse) and the swallows. 

Upward of 75 species and subspecies of warblers are known within 
the limit- of the United States, and a majority of these occur in the 
West, though perhaps they are not so abundant individually as in 
i he Mississippi Valley and Appalachian region. 

The genus Dendroica. as the one best exhibiting the characteristic 
traits of the group, may be taken as the type of the family. There 
are about •"><> species and subspecies of the genus in this country, and 
the ones whose food i< discussed in the following pages occur in 
California and on the Pacific coast generally. 

In a resume of the food of the warbler family one is impressed 
with the general noxious character of the insects which compose it. 
The order of I Iemiptera. commonly called bugs, contains some of the 
worst insect pests that afflict mankind. Moreover, from their small 
size and unobtrusive habits they are not eaten by many of the larger 
birds and are difficult to exterminate by the devices of man. But 
in some of their multiple forms they are preyed upon by the warblers 



Bull. 30, Biological Survey, U. S Dept. of Agriculture. 



Plate III. 




Audubon Warbler Dendroica audubonp. 



WARBLERS. 1 3 

to an average extenl of more than 25 percent of Hie whole food. 
Most of the oilier insect Pood, also, i.s either of ;i noxious or neutral 
description, and the vegetable portion i- so small that ii may l>e dis- 
regarded. There is probably no liner tribute to the beneficial char 
acter of these birds than thai of Dr. Elliot (one-, who says: 

Willi tireless industry do the Warblers befriend the human race; their uncon- 
scious zeal plays due part in the nice adjustment of Nature's forces, helping to 
bring aboul the balance of vegetable and insect life, withoul which agriculture 
would be in vain. They visit the orchard when the apple and pear, the peach. 
plum, and cherry, are in bloom, seeming to revel carelessly amid the sweet- 
scented and delicately tinted blossoms, bul never faltering in their good work. 
Thej peer into the crevices of the bark, scrutinize each leaf, and explore the 
very hearl of the buds, to detect, drag forth, and destroj these tiny creatures, 
singly insignificant, collectively a scourge, which prey upon the hopes of the 
fruit-grower and which if undisturbed, would bring his care to naught. Some 
Warblers Hit incessantly in the terminal foliage of the tallesl trees; others hug 
close to the scored trunks and gnarled boughs of the foresl kings; some peep 
from the thicket, the coppice, the impenetrable mantle of shrubbery that decks 
tiny watercourses, playing at hide-and-seek with all comers: others more 
humble still descend to the ground, where they glide with pretty, mincing steps 
and affected turning of the head this way ;.nd that, their delicate flesh-tinted 
feel just stirring the iayer of withered leaves with which a past season carpeted 
t he ground. 

Following is a list of insects, mostly beetles, identified in the stom- 
achs of the warblers examined. A number of these had been eaten 
by nearly every species : 

COLEOPTERA. 

Coccinella I. californica. Crepidodera helxines. 

S( ymnus pallens. Epitrix parvula. 

scumiiii.s marginicollis. Briichus pauperculus. 

Hcymnus sp. now Blapstinus pulverulentus. 

Wicrolipus laticeps. Votoxus alamedec. 

Helanophthalma americana. \ nthicus diflicilis. 

[phodiusj'ugifi ons. Diodyrhynchus byturoides. 
Diachus auratus. Vpion vespertinum. 

Gastroidi a cyam a. Onychobaris insidiosa. 

I iidhrni irn soror. Balaninus sp. 

Ill M I 1*11 KA. 

Saissi i in oh >i . \spidiotus rapax. 

At IM BON WARBLER. 

i Dendroica a uduboni. i 

i Plate HI. i 

The Audubon warbler is well distributed over the Pacific coast 
region, breeding in the mountains and descending in winter to the 

valleys and plain- of California. It is one of the most abundant 

a Birds of the Colorado Valley, p. 201. 



44 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

species, and may be considered as typical of the genus, especially in 
the matter of food. In the winter season it is a frequenter of 
orchards, gardens, and dooryards where it pursues its business of 
insect hunting with a persistent assiduity worthy of all praise. At 
this season it is very familiar and easily approached. 

In investigating the food of the Audubon warbler 383 stomachs 
have been examined. They were taken from July to May inclusive. 
Geographically they are distributed from the San Francisco Bay 
region southward to San Bernardino, and probably give a fair idea 
of the winter diet of this bird in California. The food consisted of 
nearly 85 percent of animal matter (insects and spiders) and a little 
more than 15 percent of vegetable. 

Animal food. — The largest item of animal food is Hymenoptera — 
wasps and ants — which aggregate a little more than 26 percent of the 
whole. By far the greater number of these are ants, and as plant- 
lice also are eaten to a considerable extent, it is probable that many 
of the ants are species that take care of the lice. The other members 
of this order are mostly rapid fliers, so the inference is that they were 
caught on the wing. The greater number were eaten in the fall and 
spring months. In our record May appears as the month of least 
consumption — 6 percent. August is the month of greatest consump- 
tion — 61 percent. This record, however, probably is unreliable, as 
but one stomach was taken in this month. A few were identified as 
belonging to parasitic species. 

Flies (Diptera) are represented in the stomachs of the Audubon 
warbler to the extent of a little more than 16 percent, or one-sixth of 
the whole food. This is one of the largest, if not the very largest, 
record of this order of insects eaten by any bird except some of the 
swallows. Even the so-called flycatchers do not eat so many flies as 
this warbler — in fact, the name ' wasp-catchers ' would be much more 
appropriate for that family. The flies eaten by the Audubon war- 
bler must have been caught in mid-air, for flies as a rule do not allow 
themselves to be captured without at least attempting to escape. 
These insects are so soft-bodied that it is not often possible to deter- 
mine more about them than that they are Diptera. Two families 
were identified — Muscidfe, the family of the common house fly, and 
Tipulidse, or crane-flies, the long-legged mosquito-like creatures other- 
wise known as " daddy-long-legs." Most of the Diptera, however, 
are the smaller species, such as gnats, which fly in swarms, and being 
rather sluggish are more easily captured. They are eaten with 
remarkable regularity during the whole season, with no decided de- 
crease in the winter months— in fact, mere were eaten in January 
than in either September or April. March is the month of maximum 
consumption, when Diptera constitute over 54 per cent of the whole 
food. 



WARBLERS. 45 

Bugs collectively amount to nearly 20 percent, of which a little 
more than 4 percent arc scales and plant-lice. The black olive scale 
(Saissetia oleoe) and another species (Aspidiotus rapax) were found 
in 15 stomachs. Plant-lice (Aphididae) were contained in 39 stom- 
achs, and from the numbers eaten appear to be favorite food. Sev- 
eral stomachs were entirely lilled with them, and the stomachs in 
which they were found contained an average of Tl percent in each. 
The remainder of the hemipterous food, more than 15 percent, is 
made up of stink bugs, leaf-hoppers, and tree-hoppers, with a con- 
siderable residue of other remains not further identified. Bugs, as a 
whole, are eaten rather irregularly, and the greater number are eaten 
in the fall months, after which the number consumed gradually 
decreases. Caterpillars are eaten rather regularly by the Audubon 
warbler, but not in great numbers. They amount to nearly 14 percent 
of the food of the season, though this figure includes a few moths and 
chrysalids. Some cocoons of tineid moths were in several stomachs. 

Beetles of all kinds aggregate something more than percent of 
the whole diet. They belong to several families, but the snout-beetles 
are most prominent. The others belong to about a dozen families, 
and, except a few carrion and ladybird beetles, are injurious. A few 
insects other than the above and some spiders, in all a little less than 
2 percent, make up the rest of the animal food. 

Vegetable food. — The vegetable food of the Audubon warbler con- 
sists of fruit, weed >v(h\. and a few miscellaneous substances. As the 
bird does not visit the fruit-growing regions during the fruit season, 
it is not chargeable with injury to cultivated crops. Almost all the 
fruit eaten is wild and of no value, though in the fall it probably 
feeds to some extent upon various belated products of the orchard. 
The total of fruit for the season is less than 5 percent, of which the 
greater amount is eaten in the autumn and early winter, after which 
the quantity is unimportant. 

The most prominent item of vegetable diet, however, is weed seed. 
This is eaten to the extent of a little more than 9 percent of the whole 
food, and is taken in almost every month of the bird's stay, the 
greater quantity in winter. Something more than 31 percent was 
eaten in December. 22 in January, and 31 in February, after which 
it decreases regularly to April. One of the mist important seeds 
eaten by the Audubon warbler is that of the poison oak' {Rhus diver- 
siloba (PI. IT. fig. 9). In mosl cases the whole seed is not eaten by 
this bird, but only the waxy outer coating, which is easily identified by 
certain woody granule- which it contains: hence the bird does not aid 
in the distribution of these noxious plants. The remaining vegetable 
food, amounting to less than 2 percent, consists principally of rubbish. 



46 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

SUMMARY. 

It must be evident to the most casual reader that this bird is a 
valuable asset in the orchard and garden. The great bulk of its 
food, both animal and vegetable, is composed of elements the elimina- 
tion of which from the farm is a benefit. As has been elsewhere 
pointed out, the destruction of insects during winter or in early 
spring is more useful than in the height of the midsummer abun- 
dance, for in spring the progenitors of the season's broods are 
destroyed and with them the possibility of thousands of progeny. 

M VKTLE WARBLER. 

(Dendroica corona la.) 

This is another winter visitant in California. Only 10 stomachs 
of this species have been examined, but the contents show the pre- 
dominant food characteristic of the genus. There is one point, how- 
ever, which is worthy of passing note. One of . these stomachs was 
completely filled with greedy scales {Aspidiotus rapax), with the 
exception of a small fragment of a beetle; another contained remains 
of the black olive scale, and still another some scales not identified. 

T( >WNSEND WARBLER. 

i Dendroica townsehdi. I 

The Townsend warbler, like the Audubon, summers in California 
only in the mountains. During the migration and in winter it visits 
the valleys. Like other members of the family it is an insert eater 
almost exclusively, and does not eat fruit or other farm products. 
Thirty-one stomachs were taken in the four months from October to 
January inclusive, in the region from Pacific Grove to Watsonville. 

As our stomach examinations disclose the fact that the food of this 
warbler agrees closely with that of others of the same group, a Pair 
idea of the diet lor the above months is obtained. 

Animal food. — The animal food consists of insects and a few 
spiders, and amounts to over 95 percent of the food during the time 
specified. Of this, bugs make" up 1-2 percent, mostly stink-bugs 
(Pentatomidse) and a few leaf-hoppers and scales. The former 
appear to he a favorite food. Although these insects are eaten with 
considerable regularity by most of the warblers of this group, they 
;irc not usually taken in great numbers, but the Townsend warbler 
eats many, and several stomachs were entirely filled with them. 

ETymenoptera, consisting of both wasps and ant-, are eaten to the 

( \l< lit of 25 percent (if the food. Most of them ;i re winged speClBS. 

Perhaps the most striking point in the food of this bird is the great 



w akuu.i;.-. 17 

Dumber of weevils or snout-beetles represented. They amount to over 

i 20 percent of the food, w hile all oilier beetle- form less than 1 percent. 
The greater number of these insects were of the species Diodyrhyn- 
chus byturoides, a weevil which destroys the staminate blossoms of 
coniferous trees. Five stomachs contained, respectively, 68, 65, 53, 
50, and 35 of these beetle-. <>r 271 in all. Moreover, each of these 
stomachs contained fragments which could not be satisfactorily iden- 
tified; probably these were the same species, so thai the total con- 
tained in the 5 stomachs is probably nearer 300. Several other 
stomachs contained fewer of these weevils. Representatives also of 
another family of snout-beetles very destructive to timber were pres- 
ent in a few stomachs. These were the engravers (Scolytidae), which 
lay their eggs beneath the bark of trees, where they hatch, and the 
larvae bore in every direction. Caterpillars and a few miscellaneous 
insects and some spiders make up the remainder of the animal food. 

Vegetable food. — The vegetable matter, which amounts to less than 
5 percent of the whole, consists of a few seeds and leaf galls. As the 
galls in most cases contained small larvae it i- a question if they 
should not be reckoned as animal food. 

SUM MARY. 

While this can be considered as only a preliminary study of the 
food of the Townsend warbler, the thoughtful reader can not fail to 
be impressed by the fact that this bird exhibits some very valuable 
economic traits, especially in it> relation to the forest. The stomachs 
containing the pine-eating weevils were from birds killed in the pine 
forests of Pacific Grove, near Monterey, as also were those containing 
the engraver beetles. Of the 30 stomachs examined, 19 held the 
remains of weevils, from which it would appear that these insects 
are preferred as an article of food. As this group of beetles con- 
tains some of the worst pests of the forest and orchard, any bird that 
eats them so freely must be considered as performing a most welcome 
service. 

81 M Mil: WARBLER. 
i i h ndroica u stivo, subspp. I 

The summer warbler, yellow warbler, or summer yellowbird, a- it 
is variously called, is represented in the West by two subspecies, one 

of which visits California only a- a migrant. The other, which does 
not differ essentially from the eastern form, is a rather common sum- 
mer resident throughout the valley ami foothill regions. In the East 
this bird is fairly dome-tie in it- habit-, and may often be seen about 
gardens and orchards, or in rose bushes nearer the house. In Cali- 
fornia it is not quite so familial-, but i- becoming so and probably will 



48 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

soon acquire the habits of its eastern relative. From the material at 
hand this warbler appears to be even more exclusively insectivorous 
than the species last discussed. This may arise from the fact that 
it stays in the fruit districts during summer, -when insects are most 
numerous; but it must be remembered that this is also the season 
when fruit and vegetable food generally are most abundant. 

William Prond, of Chico, Butte County, thus recounts the efficient 
service of this and other warblers : 

On Rancho Chico is a hue collection of roses, all of which are more or less 
liable to attacks from Aphis rosea, but are perfectly free from other insects. 
I attribute this to the protection of small birds, among the most active of which 
are Dendroica cestiva, * * * Helminthophila celata, Regulus calendula. 

The following statements in regard to the food of the summer 
warbler are based on the examination of 98 stomachs, all collected 
from April to October, inclusive. 

Animal food. — The animal food, composed entirely of .insects and 
a few spiders, amounts to over 97 percent. The largest item is 
Hymenoptera, which amounts to over 30 percent, about half of which 
are ants. The remainder are small bees and wasps, some of which 
are probably parasitic species, though none were positively identi- 
fied. The insects of this order must be favorite food, as they are 
eaten with remarkable regularity and constitute an important per- 
centage of the diet in every month represented. Caterpillars, with a 
few moths, aggregate over 18 percent. The greater number arc 
eaten in spring and early summer, but in fall they give place to other 
insects. 

Beetles form nearly 16 percent of the diet, and embrace about a 
dozen families, of which the only useful one is that of the ladybirds 
(Coccinellida?), which are eaten to a small extent. The great bulk 
of the beetle food consists of small leaf-beetles (Chrysomelida^). with 
some weevils, and several others. One stomach contained the remains 
of 52 specimens of Notoxus alamedce, a small beetle living on trees. 
Bugs (Hemiptera) constitute over lit percent of the food, and arc 
eaten regularly every month. Most of them consist of Leaf-hoppers 
(Jassidse) and other active form-, but the black olive scale appeared 
in a number of stomachs. Plant-lice were not positively identified, 
but some stomachs contained a pasty mass, which was probably made 
up of these insects in an advanced stage of digestion. 

Flies seem to be acceptable to the summer warbler; they are eaten 
to the extent of nearly 9 percent. Some of them are of the family 
of the house fly. others are Long-legged tipulids, but the greater num- 
ber were the smaller specie- commonly known ;i> gnats. A few 
small soft-bodied Orthoptera (tree-crickets), a dragon-fly, and a few 
remains not identified, in all about 5 percent, made up the rest of 
the animal food. 



WABBLERS. 



49 



Vegetable food. — The vegetable portion is only about '2\ percent. 
Xcarlv all of this was fruit pulp contained in a single stomach. 
This, with one or two seeds and a few accidental bits of rubbish, 
makes up the whole vegetable contingent, which, therefore, may be dis- 
missed without further comment. 

FOOD Ol NESTL] NGS. 

Some idea of the amount of insect food eaten by warblers may be 
obtained by watching the feeding of their young by the parent birds. 
A nest of the summer warbler containing two young, about a week 
old when discovered, was watched for six hours distributed over three 
days. The nest was situated in a prune tree in an orchard, and it is 
practically certain that all the food for this family was obtained in 
the orchard. The results of the observation appear in the following 
table: 



Forenoon. 


Afternoon. 


Date. 

Houroi obsei 

Nation. 


Number 
of feed- 
ings. 


Hour of obser- 
vation. 


Number 
of feed- 
ings. 


June 12 




• 3. 26-4. 26 


21 


June 1 I 8.21- 9.21 
June 14 10.34-11.34 
June 15 8.00-9.00 


31 
32 

36 


4. 36-5. 36 
1.11-2.11 


31 
30 



In six hours 181 feedings were observed, an average of 30 J per 
hour. As there were only two young, it follows that each nestling 
was fed 15 times per hour, or for a day of fourteen hours 210 times. 
Both parent birds took part in feeding the young, but it was noted 
that the female visited the nest most frequently. 



SCMMARY 



From the above facts it is evident that the presence of a few 
warbler nests in an orchard goes far to safeguard the trees from 
attacks of insect enemies. The inference is plain that the presence 
of insectivorous birds should be encouraged by the orchardist by 
every means in hi power. The summer warbler is, if possible, even 
more completely beneficial in it- food habits than the Audubon 
warbler. Its animal food in relation to man i> almost entirely nox- 
ious or neutral, and it eats so little vegetable food that its character is 
of but slight consequence. 

WESTERN YF.I.I.OWTIIROAT. 



(Geothlypis trichas subspp.) 



In California the yellowthroat i> an inhabitant of marshes and low, 
bushy place-, among titles or willows. While it is an insect eater of 
9370— Xo. 30—07 £ 



50 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

the highest order, it does not so directly affect the interests of horti- 
culture as it would if it frequented orchards and gardens. It may be 
said, however, that as the swamps and thickets in which it lives are 
the recruiting grounds for many orchard pests, the bird that destroys 
them in their native haunts is by no means without economic value. 

In a somewhat restricted investigation of the food of this bird 114 
stomachs, taken in every month except January, were examined. 

Vt </< tahli food . — A few seed- and bits of rubbish is the sum total of 
the vegetable food, and it is probable that these were taken accident- 
ally. Some of the ants of California store tip seeds, and when snap- 
ping up ants the yellowthroat probably takes the seeds along with 
them. 

Animal matter. — The animal matter amounted to 09.8 percent of 
the total food. The largest item is Hymenoptera, amounting to 35 
percent, of which about half is ants and the remainder wild bees, 
wa>|)>. etc. 

Heiniptera amount to 28 percent, and are made up of leaf-bugs, 
leaf-hoppers, tree-hoppers, plant-lice, scales, and probably some others 
not identifiable. The black olive scale was found in a few stomachs 
and plant-lice in one. but the other families were a pretty constant 
component of the food in every month. 

Beetles were eaten to the extent of nearly 15 percent, and are mostly 
harmful species, the exception being a few coccinellids of the genus 
Scymnus, which, however, do not amount to 1 percent of the whole. 
Weevils and others of the more common families make tip the rest of 
this portion of the diet. The three orders of insects mentioned above 
form the great bulk of the food of the yellowthroat. and are regularly 
eaten throughout the year. 

Caterpillars and moths comprise 5 percent, but. so far as the 
stomachs at hand -how. are eaten Aery irregularly and do not appear 
on the preferred list. The same may be said of Diptera, though they 
amount to 12 percent, but in several months none were eaten, (ira^s- 
hoppers were found in only four stomachs, but one of these contained 
nothing else. Spiders are taken to the extent of nearly 4 percent, but 
in ome months none were found and onl\ a trace iii other-. 

' ' S4AB . 

f the food of t] ' 'hroat 

evident that the horticulturist has nothing tc fear from this 
bird should it change its habitat and become an inhabitant of 
orchard- and vineyard-. It is practically wholly insectivorous, and 
the insects it eats are either harmful or of little economic value. It 
cat- no fruit or grain, nor. so far as known, any other useful product. 
Like other members of the family, its life is passed in unceasing 
search for insects. 



WABBLERS. 51 

• iE \ m.i I ROW \ id w VRBLJ R. 
i ih Iminthophila << lata subspp. i 

The genus Helminthophila is next to Dendroica in the number of 
species and subspecies ii contains, but -till falls far below it. Several 
species occur in California, bul the one under consideration is prob- 
ably the most important. ( )nly 65 stomachs were available for exami- 
nation, but they confirm the evidence already obtained from other 
species. 

I egetabh food. Less than 9 percent of the fond is vegetable mat- 
ter, and is made up of 3 percent of fruit and rather more than 5 per- 
cent of various substances, such as leaf galls, seeds, and rubbish. 
Fruit was found in only a few stomachs, but the percentage in each 
was considerable; figs were the only variety identified. 

Animal food.- The animal matter in these stomachs amounts to 91 
percent of the food. Hemiptera are the largest item and amount to 
over 25 percent, mostly leaf-bugs, leaf-hoppers, plant-lice, and scales. 
Plant-lice were found in only one stomach and scales in 5, of which 3 
contained the black olive species. Beetles amount to about 19 percent 
of the food, and with the exception of a few Coccinellidae are of 
harmful families, among which are a number of weevils. 

Beetles and him- are the two order- of insects that are not only 
eaten to the greatest extent hut are taken with great regularity, and 
form a respectable percentage of the food in every month. 

Caterpillar- are eaten rather irregularly, though they aggregate -_ ; 1 
pel-cent for the year. Stomachs collected in several months contained 
none, while in other- they amounted to more than half the food. 
Probably the examination of a greater number of stomachs would 
show more regularity in the consumption of these insects. 

I [ymenoptera amount nearly to 1"> percent, and are mostly small 
wasps, though some ants are eaten. This is the smallest percentage 
for this order that has yet been found m the food of any warbler. 

Flies arc represented by less than 1 pcrc.au. which is unusually 
mall. Pei ha p thi ai bier lack - i \\^ skill to catch uch ag 
insects. Seven percent of pider were found in the stomachs, the 
largi I percentagi ot tin i creatun | - 1 in; warbler. 1 hi again 
• l t 1 1 ' u ful in hunting slug 

gish gam such a 

GOLDEN IM I . I :< >l. \ I I I > WARBLER. 
i IViteonia pii-tilhi subspp. i 

The golden pileolated warbler is another of the small birds that 

summer here and there on the Pacific coast, mostly in willows and 



52 BIKDS OF CALIFORNIA AFFECTING FEUIT INDUSTRY. 

other shrubbery, but not rarely in the orchard. During the migra- 
tion it is common and widespread. 

Fifty-two stomachs of this bird have been examined, and though 
the evidence is somewhat fragmentary, it suffices to reveal the general 
character of the food. 

Animal food. — Animal matter amounts to over 93 percent, vege- 
table to less than 7 percent. Of the former, the larger item is Hemip- 
tera. which aggregates over 35 percent. The black olive scale was 
found in four stomachs, but leaf-hoppers make up the bulk of this 
portion of the food. Hymenoptera stand next in importance, with 31 
percent, made up of both wasps and ants. 

Flies are eaten to the extent of 11 percent, and in connection with 
the Hymenoptera proves what observation of its habits indicate, that 
this bird gets much of its food when on the wing. A good many of 
the insects were the tipulids, or crane-flies. 

Beetles of half a dozen different families were 1 eaten to the extent 
of about 9 percent. They were mostly leaf-beetles (Chrvsomelida?), 
with a few weevils and one or two others. Xo coccinellids were 
found. 

Somewhat less than 5 percent of the food consists of caterpillars. 
They do not appear to be favorite food, for they are eaten very 
irregularly. Spiders also are taken only sparingly, and form but 
little more than 1 percent of the total food. 

Vegetable food. — The vegetable food, less than 7 percent of the 
total, is made up almost entirely of fruit pulp, and was eaten in the 
months of September and October. 



The foregoing hasty review of the food of the golden pileolated 
warbler shows that its food habits are practically the same as those 
of other members of the family. The food is largely composed of 
insects, and ils two most prominent elements are Hymenoptera and 
Hemiptera, which arc eaten extensively and very regularly through 
the year. The other component^ of the diet apparently are taken 
with less regularity . 

WLSTIRN MOCKING B1KD. 

i •• • lev ) ■ 

The mocking bird has always been held in Mich high esteem as a 
singer that perhaps it would be useless to attempt to add to the 
bird's repute by showing that it > food habits arc of a high order of 
economic interest. Moreover, the title of the mocking bird to be 

ranked as an economic benefactor is not quite clear, for, though it 



WES ii i;n m<>< Kl \'(, BIBD. 

does considerable good by the destruction of harmful insects, it eats 
much fruit, and from the Southern States, particularly Texas and 
Florida, where fruit raising is an important industry, have come 
bitter complaints against it. In Florida the bird is said to attack 
grapes and oranges, and in Texas it is asserted that figs arc to be 
added to its food list. 

In California the mocking bird is a common resident only in the 
southern half of the State and is very common only in restricted 
portion-. NO serious complaints of the bird's depredations in thif 
State have yet been made, but this perhaps is due to the fad that 
mocking birds arc rare in sections where cherries and the smaller 
deciduous fruits arc grown. Where mocker- arc most abundant, 
citrus fruit- are the principal crop and the birds do not appear to 
molest them. 

While a number of stomachs of this bird have been examined, they 
are too few and too unequally distributed over the region under 
investigation to justify final conclusions with regard to the animal 
food: -till they furnish information of value. It so happens that 
33 stomachs were taken between July L8 and August L8, and another 
a few days later. All hut one of these stomachs were from the region 
about Los Angeles, and this one was collected at Fresno. The av- 
erage, therefore, is a little more than one stomach a da}^ for this 
period, and gives a fair idea of the food for the time and locality. 

The first analysis gives 23 percent of animal matter and 77 percent 
of vegetable. There was no stomach which did not contain some 
vegetable food, while 10 had no animal matter. 

An'niKiI food. — Beetles of several families formed a little less than 
1 percent. Ilymenoptera, largely ants, were eaten to the extent of 
somewhat more than 10 percent. Grasshoppers constituted the larg- 
est item of animal food, and amounted to 11 percent of the whole. 
A few caterpillars and spiders made up the other 1 percent of the 
animal food. 

Vegetable food. — Of the 77 percent of vegetable food nearly 74 
percent was diagnosed as fruit. Some of this, of course, was wild, 
but blackberries or raspberries, grapes, and fi<>'s were found in many 
stomachs. Many of the birds were taken in orchards and gardens, 
and some were -hot in the very act of pilfering blackberries. Others 
were taken in a wild arroyo away from cultivation. The only species 
of wild fruit- that were identified were elderberries, which were 
found in a few stomach-. The other vegetable matter was made up 
of several element-. Of these, the seeds of poison oak' (PI. II. fig. 9) 
are perhaps the most conspicuous, and one stomach was entirely filled 
with them. A few weed seeds and some rubbish completed the vege- 
table part of the food. 



54 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

Besides the 34 stomachs already discussed, L9 others were examined. 
Imt as they represent nine months of the year they are too few to 
afford a criterion of the usual food for those months; but they give 
a hint at least of what is eaten at other times than midsummer. 
Two stomachs were taken in March, one of which was tilled with ani- 
mal food, and the other also, except 1 percent of vegetable rubbish. 
The animal portion consisted of harmful insects, except one lizard. 
This seems peculiar food for a mocking bird, and is to be considered 
beneficial. The one stomach taken in May was filled with seeds of 
poison oak. A stomach collected in June contained s percent of 
caterpillars; -mail fruit, probably wild, constituted the rest of the 
contents. Six stomachs taken in August contained 22 percent of 
animal matter to 7^ of vegetable. The animal food consisted of 
beetles, ants, and grasshoppers. The vegetable portion was made up 
of some wild grapelike fruit and a little fig pulp with some elder- 
berries: Of four stomachs taken in September, one was tilled with 
insects and spiders. The three others contained a few wasps, with 
fruit and other vegetable matter. The only insect to be considered 
useful was one carabid beetle. Of the three stomachs collected in 
October, one was filled with the seeds and pulp of grapes and figs; 
one contained 27 percent of grasshoppers and 73 percent of some wild 
berry not positively identified, while the third contained a few grass- 
hopper remains and 92 percent of wild seed. The stomach collected 
in December was filled with seeds and pulp of figs and grapes. One 
stomach was taken in January which contained 70 percent of harmful 
insects and 30 percent of seeds of poison oak. 

FOOD or YOUNG. 

Among these stomachs was one of a nestling about a week old. It 
contained 92 percent of grasshoppers and cricket- and 8 percent of 
some wild fruit. So far a- it goes, this indicates that mockers follow 
the genera] rule and" feed their young largely on animal food of the 
softer kind — that is. grasshoppers instead of beetles. 

SUM MARY. 

Reviewing the contents of the 52 stomachs we find 29 percent of 
annual matter and 71 of vegetable. Of the animal food the largest 
item i> llyinenoptera. L0 percent, and then in order. Orthoptera 7 
percent. Coleoptera 6 percent. Lepidoptera 5 percent, miscellaneous 1 
percent. The vegetable Pood consists of 50 percent of fruit and 21 
percent of seeds and other item-. These results prove that the mock- 
ing bird eat- insects t<» a considerable extern, but they are not con- 



i ai.i i ORNl \ in i; w-ii i.i;. .,'> 

elusive as to the elements of its preferred diet. Ii is evident thai it 
i- I'oml of fruit, and where abundant the bird may become :i menace 

to t he orchard and \ ineyard. 

CALIFORNIA THRASHER. 

i In i os (oma i < ,1 i r i rn. i 

Thrashers are eminently bird> <d" the underbrush. "N^^li i 1<" they 
occasionally alight on trees at some height from the ground, 1 1 1« - \ 
are more frequently seen under bushes or skulking out of sight in 
some almost impenetrable thicket of briars. When, however, the 
thrasher wakes in the morning and feels his soul overflowing with 
song, he perches on the topmost twig of a tree and lets the world 
know thai he is there and believes that life is worth living. 

The food of the thrasher is obtained on or near the ground. The 
long curved bill of the California species is probably used much as 
many birds use their claws to dig among dead leaves and other rub- 
bish for insects. The bird is not fastidious in it- diet, and examina- 
tion of the stomachs reveals a good many hit- of dead leaves, rotten 
wood, plant stems, which are carelessly taken along with more 
nutritious morsels. 

An examination of 82 stomachs of this species shows that vegetable 
food exceeds the animal in the proportion of 59 to 41. In the eastern 
species ( T. rufum ) the ratio is 36 to 64. This result is rather >ur- 
prising, for, as a genera] rule, California birds eat a larger propor- 
tion of animal food than do the most nearly related eastern species. 

A a '/in dl food. — A.s the thrasher is eminently a ground forager it 
would naturally he expected to find and eat many ground-living hec- 
tic-. Of these the Carabidae are the most important, owing to their 
predaceous habits; so a separate account of this family was kepi. 
The result shows that they enter the food of the thrasher to the extent 
only of 3.8 percent, while all other beetles amount to nearly 6 percent. 
Of these, the darkling beetles (Tenebrionidae) are the most numerous, 
and the May hectic- (Scarabaeidse) next. But very few weevils or other 
species that Live on tree- or foliage were found. Of all the insects, 
I Iymenoptera are the most abundant, as they are also the most con- 
stant element of the thrasher's food. About half of these are ant-, 
the rest wasp- and bees. Ant- naturally are the insects most often 
found by this bird, a- many species live on the ground and among 
rubbish and rotten wood. The occurrence in the food of wasps and 
bees, on the contrary, i- somewhat of a surprise, as they are mostly 
sun-loving insects more often found on flowers or the leaves of trees 
than under bushes or thicket- where the thrasher delight- to forage. 
Together they make up something more than L2 percent of the food 



56 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

of the year. Two specimens of worker honey-bees (Apis mellifera) 

were found in one stomach. Xone of the other Hymenoptera was of 
specially useful species. 

Caterpillars, cocoons, and moths amount to a little more than 8 per- 
cent of the food, and the greater number were eaten during the win- 
ter months. It is probable that they were hibernating and were 
raked out from under dead leaves or other rubbish. A few bugs, 
flies, grasshoppers, and spiders make up the rest of the animal food — 
about 6 percent. Spiders and myriapods amount to a little more than 
(') percent. 

Vegetable food. — The vegetable food may be divided into three 
parts: Fruit, poison-oak seeds, and miscellaneous vegetable matter. 
Fruit represents nearly 18 percent, but it probably is not of much 
value. Several stomachs contained pulp that could not be identified 
with certainty, and might have been that of some cultivated variety. 
Seeds of Rubus fruits (blackberries or raspberries) were found in 1'2 
stomachs out of the 82. These, however, are as likely to have been 
wild as cultivated. Elderberry seeds were discovered in 10 stomachs, 
Cascara, or coffee berries (Rhamnus calif omicus) , in 5. and manzan- 
ita berries in 1. The seed of poison oak {Rims diversiloba, PI. II, 
fig. 0), and a few of the nonpoisonous species of Rhus were eaten to 
the extent of 14 percent of the food. They were not found in many 
stomachs, but appear to be eaten in considerable quantities when 
eaten at all. The thrasher must be added to the list of birds that 
assist in the dissemination of the seeds of this noxious plant. 

The miscellaneous part of the vegetable food amounts to over 26 
percent, and is made up of mast, weed seed, galls, and rubbish. The 
mast was not further identifiable. Most of the seeds were so broken 
and ground up that only a few species were identified. Two stom- 
achs contained remains of grain — wheat in one and corn in the other. 
Leaf galls were found in several stomachs, and rubbish in quite a 
number, though here again it is difficult to draw the line between food 
proper and stuff that is accidentally picked up with it. 

si M MARY. 

Although the thrashers eat some fruit, most of it is wild and of no 
value. Moreover, the bird's habits are such a- to preclude the like- 
lihood that it will ever become a resident of orchards. Grain evi- 
dently i- not a favorite food, and if it were it i- doubtful if the bird 
would leave it> chosen haunt- for the sake of procuring it. It is not 
probable that the California thrasher will ever become of special 
economic interest unless under very exceptional circumstances. In 
the meantime it performs it- part in the great work of reducing the 
vast numbers of insect-. 



WRENS. 57 

WRENS. 

Since the time to which history runneth no! the wren family, pep- 
resented by one or oilier of n- members, has attached itself to the 
abodes of man. Wherever man settles some member of this group is 
ready to greet him, to take advantage of his improvements, and to 
aid in the fight against his insect enemies. The common wren of 
Europe and the house wren of eastern North America habituall\ 
choose crannies in buildings or fence- for nesting places, or if hollow- 
trees are selected they usually are near human dwellings, preferably 
fruit tree- in orchards or gardens. When civilization was pushed to 
the Pacific coast, wren- were there ready to welcome the new order of 
things. In food habits the wrens proper (Troglodytinse) are largely 
insectivorous. While occasionally they eat a seed or a hit of fruit, 
the quantity taken by most species during the year is so small in 
comparison to the animal portion as to he insignificant. The insects 
eaten by the wren- are mostly noxioii- species, such as infest the 
foliage and branches of trees and shrubs, and the domestic habits of 
the wren- enable them to attack these pests in the very places where 
they are mo-t harmful — that is. in the garden and orchard. The 
predaceous hectic- (Carabidae), which live mostly on the ground, are 
protected from the wrens by this very habit, as the latter seldom for- 
ages in such place-. Moreover, the species most valuable to man are 
rather large prey for such -mall birds. 

BEWICK WREN. 

(Thryomanes beivicki subspp.) 

The Bewick wren i- one of the -pedes which to a considerable 
extent occupies in California the place of the house wren in the East- 
ern State-. The uesting habit- of the two are practically identical, 
and the economic value of the former is just as great as that of the 
latter. 

Investigation of this bird"- food i- based upon the examination of 
L46 stomachs taken in ^\cvy month of the year. Of its diet for the 
year a little more than ( .>7 percent con<i<ts of insects and less than 3 
percent of vegetable matte]'. 

Vegetable food. — The largest quantity of vegetable matter was 
eaten in December and January and formed about L2 percent of the 
food in each of these month-. In three months — March. .June, and 
September — no vegetable food was found in the stomachs. It is 
hardly probable, however, that such would always be the case in these 
months. What was supposed to be pulp of fruit was found in one 
stomach. This was the only vegetable substance noted that could pos- 
sibly be useful to man. Six stomachs contained seeds more or less 
broken, of which only one was identified, a single seed of turkey 



58 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

mullen (Eremocarpits setigerus). In one stomach was a small gall. 
and in six were various substances, sueh as hits of dead leaves, plant 
stems, and rotten wood, which may properly be denominated rubbish. 

Animal food. — Of the animal food various families of bugs 
(Hemiptera) make up the largest percentage. One of the most 
interesting items is the black olive scale, which was found in a num- 
ber of stomachs but docs not appear to be eaten extensively. The 
great bulk of the hemipterous food was made up of leaf-bugs, stink- 
bugs, shield-bugs, leaf-hoppers, tree-hoppers, and jumping plant-lice, 
though there were representatives of other families. The aggregate 
of the Hemiptera eaten is about 31 percent of the total food. It is 
distributed with great regularity through the year and varies less 
from month to month than any other food. With the exception of 
the olive scale no specially harmful species was identified, but bugs 
belonging to the same family as the notorious chinch bug were found. 
As a vast majority of the members of this order are injurious to 
vegetation their destruction by birds must be considered beneficial. 

Beetles collectively amount to over 21 percent of the food. They 
may be placed in three groups — ladybirds, weevils, and other beetles. 
Ladybirds are probably the most useful insects of the whole order 
of Coleoptera, so that their destruction by birds is to be deplored. 
Bewick's wren eats them to the extent of a little more than 3 percent 
of the whole food. This is not a large percentage, though greater 
than could be wished. On the other hand, the bird eats weevils, or 
snout-beetles, to the extent of nearly 10 percent of its food. As all 
the members of this group (Rlrynchophora) are practically harmful, 
and some of them the Avorst pests of the orchard and forest, it must 
be allowed that we are paid for our ladybirds at a fairly good 
price A number of stomachs contained beetles of this group belong- 
ing to the family of engravers (Scolytidse) . which live under the 
bark of trees and greatly damage the timber. The stomachs of two 
wrens taken in Pacific Grove in the month of January contained 
85 and 80 percent of these beetles. 

The owners of the Pacific drove pine forests have engaged the 
services of* an expert to investigate the damage being done to the pines 
by scolytids and other bisects, and. if possible, to devise a remedy. 
I- it not evident that the bird under consideration is one of Nature's 
remedies for this evil? The trouble is that there are not enough 
birds to wage effective war against the insects. In many cases, per- 
haps in this one. man himself is partly to blame for present condi- 
tions. The birds are destroyed — destruction of the forest follows. 
By furnishing proper facilities for breeding in the shape of bird 
boxes the numbers of thi- wren in the State of California may be 
greatly increased and the forest trees correspondingly protected from 
insects. 



WRENS. 59 

Other beetles, mostly leaf-beetle? (Ohrysomelida?) were eaten to 
the extent of a little more than M percent. While nearly all of the 
leaf-beetles are theoretically liarmful none of those identified in 1 1 1«* 
food are especially destructive (<> crops. 

Hymenoptera, including both ants and wasps, aggregate a little 
more than 17 percenl of the wren's diet. They are a fairly constant 
constituent of the food and do not appear to vary much according to 
reason. The greater number was found in March, but as only two 
stomachs were collected in this month the record is not conclusive. 
Ants form about 7 percent of the food. The economic relations of 
these insects have been discussed elsewhere. Wasps make up the rest 
of the item, about l<» percent, and have no especial economic signifi- 
cance. Caterpillars and a few moths and some cocoon- constitute a 
little less than L2 percent of ilio wren's food. Contrary to what 
might be expected, not all these are taken in summer. The II 
stomachs obtained in February contained caterpillars to the amount 
of over 1"> percent of their content-. They were probably found 
hibernating in crevices of bark. A few moths were eaten, but, as 
usual, they were only a -mall item of the food. Small COCOOns of 
tineid moth- were found in a number of stomachs. 

Grasshoppers amount to I percent of the wren's diet. Most of 
them are eaten during the summer and fall, though some appeared in 
stomachs taken in January. While these insects are a favorite food 
for many bird- they art' probably rather large and too terrestrial in 
habits to he eaten in great numbers by wrens. Other insects, mostly 
Hie- and a few remain- which could not he identified, make up about 
(*> percent of the stomachs' contents. Flies (Diptera) are eaten very 
irregularly and appear not to he relished. Spiders are taken to the 
extent of somewhat more than 5 percent of the total food. As spiders 
live about tree-, bushes, fence-, rocks, and outbuildings it is not sur- 
prising that they are captured by wrens, hut the rule seems to he that 
while all insectivorous birds eat spiders to some extent no species eats 
many. 

List of insects found in stomachs of Bewick wren: 

( mi EOF! EH \. 

Cercyon fulvipenne. Diaorotica soror. 

li i ppo (in mia convergent. Cryptocephalus castaneus. 

Cocinella t. californica. Oastroidea sp. 

sci/inii us marginicollis. Bruchus seminulum. 

[phodius rugifrons. Blapstinus dilatatus. 

Uicrorhopala mould mi. Votoxus alamedw. 

Viachus a a ml us. Ceutorhynchus nodipennis. 

Crepidodera helxlnes. Pclenomw cavifrons. 

Epitrix parvula. I pion sp. 
Exetna conspersa. 



60 



BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY.' 



Silica diadema. 



HEMIPTERA. 

Sqissetia olecr. 



Remains of insects belonging to the following families were found, 
but not further identified : 



Carabidae. 

Hydrophilidae. 

Staphylinidae. 

Coccinellidn?. 

Elateridae. 

Scarabaeidae. 

Chrysomelidae. 



Muscida?. 



Emesida?. 

Reduviidse. 

Aradida?. 

Capsidse. 

Lygseida?. 

Pentatomida?. 



COLEOPTERA. 



Brucbidae. 

Tenebrioriidae. 

Anthicidae. 

Curculionida?. 

Scolytida?. 

Other Rhynchophora. 



DIPTERA. 

Tipulidae. 



HEMIPTERA. 



Corimehpnidae. 

Scutelleridn?. 

Jassidae. 

Membracidae. 

Psyllida?. 

Coccido?. 



AVESTERX HOUSE WREN. 

{Troglodytes aedon subspp.) 

The western house wren, like its eastern relative, is a common 
resident about outbuildings and other structures that offer suitable 
nesting sites and good foraging ground. In its general appearance 
and habits it is so like the Bewick wren that the casual observer is 
likely to confuse the two. Like other members of the family, it is 
largely insectivorous and rarely eats vegetable food. 

Only 36 stomachs of this species from California are available for 
examination, but the character of the food agrees so nearly with that 
of the eastern form that the general results obtained from the study 
of that subspecies may be applied to the western bird. 

Animal food. — In the 36 stomachs examined animal matter, con- 
sisting entirely of insects and spiders, formed ( .)7.5 percent, and vege- 
table food 2.5 percent. Beetles, as a whole, amount to about 20 per- 
cent ; caterpillars, aggregating 24 percent, arc taken in the earlier 
months of the year; and Hemiptera, amounting to 33 percent, are 
eaten chiefly in the la^t of the season. Grasshoppers amount to about 
5 percent, and different insects, mostly ants and other Hymenoptera, 
aggregate 15 per cent. 

Vegetable food. — The vegetable matter consists of rubbish and one 
grass seed, probably all of it swallowed accidentally. 



WRENS. 



61 



Among the 36 stomachs, oi which the record has just been given, 
were 18 nestlings, some being about a week old, others about ready 
to leave the nest. The results of the examination of these were tabu- 
lated by themselves in order to determine the differences, if any. 
between the food of the adults and that of the young. No vegetable 
matter was found in any of the stomachs, and the animal food was 
distributed among a comparatively few elements. Bugs (Hemiptera) 
are the largest item, and amount to nearly 36 percent. Caterpillars 
and grasshoppers stand next, with 17 and L6 percent, respectively. 

It is interesting to note that about three times as many grasshop- 
pers are fed to the young as are eaten by the adults. Wasps and ants 
amount to a little more than 6 percent, and are the smallest item. 
Spiders appear to the extent of a little over 11 percent. Beetles, 
however, constitute the most interesting item of the food. They 
were eaten to an average extent of somewhat more than 11 percent, 
and were nearly all ladybirds (Coccinellidae) contained in the stom- 
achs of five individuals of a hpoocl of six. The amount in each 
stomach varied from 15 to 65 percent of the contents, and averaged 
29 percent of each of the six birds. It is a question which is the more 
surprising, that this brood had eaten so many coccinellids, or that 
the others had eaten so few. Only three other stomachs contained 
any of these beetles and those were all adults. The house wren does 
not exhibit any special proclivities for ladybirds, and it would seem 
probable that in this case either other food was wanting or these 
beetles were specially abundant. 

In addition to the examination of stomachs, observations were made 
upon the feeding of nestling wrens. A nest situated in the porch of 
the house of Mr. W. O. Emerson, at Haywards, Cal., was observed 
for one-hour periods from soon after the young were hatched until 
thev were nearly ready to flv. The nest was watched at various times 



of dav. so as to include as nearly 



po 



ible all hours of davliffht. 



During the first two periods the male aided in feeding the young, 
but afterwards was not seen, and the whole care of the young de- 
volved upon the mother. The number of young probably was not 
fewer than six. Following are the result! in tabular form: 



Date. 




n. 


\ "• < noon. 


Hour oi )b- 
servation. 


Number 

of 
feedings. 


Hour of ob- 
servation. 


Number 

Of I 

li-r-.liuns. 


MavlS... 
May 19... 
May 20... 
May 21... 
May 23... 
May 26... 
May 27 


10.00-11.00 
9.36-10.35 

L0. 29-11. 29 
8.23 
8.22- 0.22 

10.3--1 11.35 


13 
16 
20 
19 


1.00-5.00 
4.30-5.30 


7 

to 


2.01-3.01 


12 






2.36 3.36 


31 


Ma- : 
May 30... 


9.20 

10. 10-11. 10 


- 











02 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

As will be noticed, the whole time of observation covered a period 
of thirteen days, although the nest was not watched every day. In 
all the not was watched for twelve hours, and the total number of 
times that food was brought to the young was 234, or an average of 
1 1 > A time- per hour. The young were fed as early as 5 o'clock in the 
morning and as late as 7 in the evening, thus making for the parent 
birds a working day of fourteen hours. Only a little plain arithmetic 
is necessary to show very nearly the number of insects destroyed by 
i hi- family in a single day. 

These observations were made with watch in hand and the time of 
each feeding noted. In many cases the parent bird Avas away in 
search of food only half a minute. Once there was a heavy mist 
nearly all day. when the mother wren was hard pressed to find food 
for the ever-gaping mouths of her young. Xo flying insects were 
abroad, and the supply of caterpillars from the immediate vicinity 
had been exhausted. In this extremity the mother turned her atten- 
tion to spiders and was seen to visitMhe interior of a summer house, 
also to investigate a pile of flower pots and tubs and to plunge into 
and under an evergreen hedge in search of something that would 
answer for food. As the nest was watched at very short range, it was 
often possible to determine the nature of the food brought by the 
parent. When the nestlings were very young, it consisted almost 
entirely of small green caterpillars, commonly called * canker-worms. 5 
Later this was varied by tipttlid flies (daddy-long-legs), -mall moths, 
and spiders. Some of the insects brought wen 1 not determinable, 
probably flies and wasps. 

SIM MARY. 

From the above sketch of the food of the house wren it will be -ecu 
that there is practically only one item to which exception can be taken, 
namely, the coccinellid beetles, or ladybugs. But the record i- so 
meager that it is not safe to draw general conclusions. Tt is probable 
that a more extensive investigation of the food of the California bird 
will show that it is entitled to the same high economic rank a- its 
sastern relat i x - 

w RSI ERK M VRSJ1 w REN. 

[lie marsh wren, as i1 
and marshy grounds, .u first thought its food might not appear to 
ln> of any economic importance, but investigation -how- that it does 
not differ from that of the orchard wrens as much as one might infer 
Prom difference of habitat. Only •'>•*> stomachs of this species have 
been obtained for examination. While this number is not sufficient 
i ,-i basis for final judgment, it suffices to -how how closely the food 
of this specie.- resembles thai of h> congeners. 



WRENS. 63 

Vegetable food, — But little vegetable food was found in the stom- 
ach of the marsh wren, and the precise value of most of that was not 
determinable. A few seeds of sedge and <,IU ' of amaranth were nil 
that were identified. The total amount was ;i trifle over 2 percent. 

Animal J<><><1. — Beetles, wasps, ants, bugs, caterpillars, and a few 
miscellaneous insects, with some spiders and snails, make up the 
bill of fare. A> with the Bewick and the house wren, bugs arc the 
largest item, but do not quite equal the quantity eaten by those indus- 
trious bug-hunters. While the Bewick eats these insects to the extent 
of 31 percent of its food, the marsh w ren eats them only to the amount 
of 29 percent. In this respect there seems to be little difference 
between the bird that gets its food from tree- ami the one that I'v^iU 
among the tules and sedges. The families represented are those of 
the assassin-bugs, damsel-bugs, leaf-bugs, stink-bugs, leaf-hoppers, 
and tree-hoppers, most of which are usually found on trees— in fact, 
one is forced to the conclusion that the marsh wren must at times 
forage upon tree- or shrubs. Scales were found in one stomach, 
which is another point of resemblance between the diet of this bird 
and that of the habitual tree inhabiters. 

In the marsh wren's food caterpillars and chrysalids rank next to 
l>u<r> in importance. They amount to about 17 percent of the whole, 
and appear in the food of every month. Cocoons of tineid moths 
were contained in a number of stomachs, another indication that the 
birds visit trees. 

Beetles constitute L6 percent of the food. While a number of the 
commoner families are represented, the terrestrial forms are rather 
more prominent than in the food of the arboreal wrens, A few cara- 
bids and a number of coccinellids together make up 2 percent of the 
food, and were the only useful insects eaten, unless the assassin-bugs 
are reckoned a- such. A- these feed on other insects they must of 
course do some good. Ant- and wasps amount to about 8 percent 
of the food, and most of them were eaten during the fall months. 
Flies, grasshoppers, dragon-flies, and a few insect remains not fur- 
ther identified make up over 11 percent of the food. They were 
eaten very irregularly. Spider- constitute somewhat more than .» 

per< ent and i u ua I ire \ en n gulai Ij eaten but i" ma H u- 

bers. Small mollusks I nail I • ■ • • eaten b; quit* a number of birds, 

I : ;: >ma h mtain I 11 ->] im 

SUMMARY. 

This brief review of the f I of the marsh wren, while not abso- 
lutely conclusive, is sufficiently near the truth to prove that the bird 
is to he ranked among our eminently useful species. Of some birds it 
has been said that their peculiar merit lies in the fact that they 
reside in orchards and cultivated ground and hence destroy insect 



64 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

pests in the very places where their mischief is done. This can not 
be asserted of the marsh wren, but it must be remembered that many 
harmful species of insects breed and live in marshes and .waste places 
as well as in grainfields and orchards, so that the birds which 
destroy them on wild lands are removing the source of supply from 
which are recruited the hosts that infest the farm. 

CACTUS WREN. 

(Heleodytes brunneicapillus. I 
(PL IV.) 

The cactus wren is so exclusively a bird of the desert and waste 1 
places that its food ma} T be thought to have little, if any, economic 
interest. It is not safe to assume, however, that the bird will never 
affect the interests of agriculture because it does not do so at present. 
Moreover, its food habits have a scientific interest which justifies a 
brief review. A number of the birds whose stomachs have been 
examined for this work were taken near orchards and grainfields, 
and there can be little doubt that, with the spread of cultivation, the 
species wall adapt itself to a somewhat different environment and 
become of economic importance. We find, in fact, that its food is 
made up of practically the same orders and families of insects that 
compose the diet of birds living on agricultural lands, but the relative 
proportions differ widely, and in most cases the species are probably 
different. 

Only 41 stomachs of the cactus wren were available for examina- 
tion. They were taken in the region from Los Angeles to San Ber- 
nardino, and from July to January, inclusive. They contained about 
S3 percent of animal matter to IT of vegetable. 

Animal food. — Beetles and Hymenoptera, the latter ants and 
wasps, were the two most important items of the animal food. Each 
made up about 27 percent of the total. The beetles belong to several 
families, but- weevils, or snout-beetles, were the most noticeable, and 
amount to somewhat more than LO percent. One tomach contained 
11 of these insects and another 1<>. while others held fewer. Only 
one specie-. Rhigopsls effracta, was identified. Five of these were in 
1 stomach. The oth< . beetli belong to mor< common families. 
Coccinellids were found in L stomach and carrion beetles in - 
They were the only insects noted that can be considered as useful. 
Hymenoptera are represented by many ants mid a few wasps. These 

are just the insects which the cactus wren might be expected to find, 
lor dry land and sunshine are the condition- which favor these crea- 
tures. Grasshoppers amount to a little more than 15 percent. This 



Bull. 30, Biological Survey, U, S. Dept. of Agricul 



Plate IV. 




Cactus Wren Heleodytes brunneicapillus couesi 1 . 



WRENS. 65 

is the <>iil\ wren thai eats these insects to any considerable extent 
except as nest lings. 

Bugs (Hemiptera) amount to only a little more than 5 percent of 
the food, which is the smallest quantity eaten by any <>f the wren 
family. This item, however, contains one unexpected element— thai 
is, I 'luck scales (Saiss itia }. These appeared in <*» stomachs, and musl 
have been obtained from trees or shrubs, possibly from fruit trees. 
hi :)ii\ case their destruction is a welcome service. Caterpillars and 
their allies (Lepidoptera) were eaten to the extent of a little more 
than 5 percent. Ajnong them were many cocoon- of tineid moths. 
indicating again that the cactus wren obtains some of it- food from 
trc»- and shrubs. A few unidentifiable insects and spiders amount 
to somewhat more than 3 percent. This is the smallest record for 
spiders of any of Lhe wren family, which is much given to eating 
these creatures, finding them in crannies in rocks, stumps, and other 
places. A few of the long bones of a tree frog were found in 1 
stomach. 

Vegetdbli food. — Seventeen percent of vegetable matter was found 
in the stomachs of this bird. This is the largest percentage found 
in the stomachs of any species of wren yet examined. The vege 
table food of the cactus wren consists of fruit pulp and weed seed-. 
The former amounts to nearly 13 percent, but in all cases where 
identification was possible consisted of wild species. Of these, only 
3 were fully identified — cactus (Opuntia), elderberry (Sambucus), 
and Cascara' (Rhamnus), the last only in 1 stomach. Nothing 
was found to indicate that cultivated varieties had been eaten. 
Seeds, which amount to ! percent, are those of the poison oak (Rhus). 
and a nonpoisonous species, with filaree (Erodium) and Amisinckia, 
most of them useless plant- or worse. 

SUMMARY. 

From this brief inspection <d* the cactus wren's food it is seen that 
it contains but little that i- useful to man, while the great bulk is 
made up of (dement- that arc or would be. harmful if present on 
cultivated land-. The bird thus sustains the good reputation of 
the rest of it- family. 

Mima; w RENS. 

Some half a dozen stomach- each of the western winter wren {Olbior- 
chilu8 Memalis paciflcus) and dotted canyon wren (Gatherpeamexi- 
canus punctulatus) and the rock- wren (Salpinctes obsoletus) have 
been examined. This number i- entirely too -mall to serve for 
specific statements in regard to their food except that it may be said 

!»o7<>— No. 30—07 5 



66 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

that it corresponds closely to that of the other species of the family 
discussed in foregoing pages. 

From this somewhat limited investigation of the food of the 
California wrens several points may be regarded as established: 
(1) That these wrens are essentially insectivorous; (2) that an over- 
whelming majority of the insects composing their food are harmful 
species; (3) that the quantity of vegetable food eaten is so small as 
to have no economic importance. 

CALIFORNIA CHEEPER. 

(Certhia familiaris Occident alls. ) 

Only 7 stomachs of the California creeper were available for 
examination, but they confirm the good opinion observers have 
formed of the habits of this bird. Like the titmice and nuthatches, 
the creeper is an indefatigable forager on the trunks and branches 
of trees, and the food it obtains there is of the same nature — that is, 
small beetles (many of them weevils), wasps, ants, bugs, caterpillars, 
and a few spiders. Of the 7 stomachs examined, only 1 contained 
vegetable food, and this had only 19 percent of seed, too much digested 
for identification. 

While the creeper is not systematically classed with the nuthatches 
and titmice, its food habits closely ally it to these birds and to the 
wrens, and whatever good is true of them applies with equal force 
to the creeper. 

NUTHATCHES AND TITMICE. 

( Paridse. ) 

Few families of birds contain so many absolutely harmless and 
thoroughly useful species as that of the nuthatches and titmice. All 
of the American species are small, and several are so minute that the 
larger species of humming birds exceed them in size. In colors they 
are neither' brilliant nor showy, black, white, brown, and gray being 
the predominant tints of their plumage. In manners and voice they 
are equally unobtrusive, and so*little do their movements attract atten- 
tion that one may be surrounded by them in the forest before he is 
conscious of their presence. More than forty species and subspecies 
of the titmouse family re-id* 1 within the limits of the United States, 
of which some fifteen live in California. 

From an economic standpoint the titmice are the reverse of insig- 
nificant. They arc essentially inhabitants of trees and shrubs, and 
obtain almost their entire living from them. Their food consists 
Largely of small insects and their egg> and larvae, and. as the individ- 
uals of most of the species are aumerous and spend all the daylight 
hours searching for food, it follows that the number of harmful 



NUTHATi ' 1 1 IS AND TITMICE. 67 

creatures they destroy is beyond calculation. As conservators of 
forest and orchards there are few birds thai compare with them. 
The insects they destroy arc largely those thai feed upon the Leaves, 
blossoms, and fruit of trees, with some that bore into the wood or 
burrow under the bark, thereby injuring or killing the tree itself. 
On the other hand, they do not prey upon fruit, grain, or other prod- 
uct of husbandry. The small amount of vegetable matter they eat 
consists principally of smal] galls, whose destruction is a benefit, with 
a few seeds and a little wild fruit. 

PYi.M V \1 THATCH. 

i sii hi pygmcea.) 

The nuthatches are small, inconspicuous birds that live upon trees 
and for the most part remain in forests or groves, though not rarely 
visiting the orchard. While allied to titmice they form a fairly well- 
defined group and can be easily distinguished from titmice proper. 
As gymnasts they probably lead the avian world. After watching 
their movements one might suppose that nature had quite exempted 
them from the operation of the laws of gravity, as the}^ move up or 
down a tree with equal facility, or along the underside of a horizontal 
branch where they inspect a promising, knot hole or cranny, appar- 
ently without the least idea that they are upside down. The food 
they obtain from trees is of the same general character as that of the 
rest of the titmouse family. 

Unfortunately only a few stomachs of these birds are at hand for 
examination — enough, however, to give a general idea of the diet. 

The pygmy nuthatch is the smallest of the group, but as a 
destroyer of noxious insects it is far from insignificant. Only 31 
stomachs of this feathered midget are available for examination, but 
the uumber is sufficient to bring out some strong points of the bird's 
diet. The relative proportions of animal and vegetable food, as indi- 
cate! 1 by the contents of these stomachs, are approximately 83 percent 
of the former to 17 percent of the latter. 

Ann, ml food. — ldie largest item of animal food is Tlymenoptera, 
composed mostly of wasps, with a few ants. They amount to about 
38 percent of the whole. Xext in order are Hemiptera, aggregating 
23 percent. A large proportion of these belong to the family Cer- 
copicla?, commonly known as spittle-insects, from the fact that they 
develop inside of a froth-like substance resembling saliva produced 
in summer upon grass and various plant- and trees. While none 
of these insects have yel become pests, there can be no doubt thai 
collectively they do considerable harm to plant-, a- sometimes they 
are very abundant and subsist entirely upon their sap. 



68 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

In this connection peculiar interest attaches to the contents of 20 
stomachs of the pygmy nuthatch from the pine woods of Pacific 
Grove, near Monterey, June 24 to July 13. Eighteen of these 
stomachs contained remains of Cercopida?, and six were filled with 
them. The average for the 18 stomachs is a little more than 76 per- 
cent of all the food. They were not identified specifically, but 
undoubtedly are one of the several species known to feed upon the 
pine. Beetles of various families form about 12 percent of the food. 
There were many weevils, or snout-beetles, in the stomachs, and some 
coccinellids, which were the only useful insects found. They amount 
to 9.6 percent, which is the largest record for any bird yet examined, 
except the vireos; but as this percentage is based upon the examina- 
tion of so few stomachs, it can not be considered as wholly reliable. 
Caterpillars amount to 8 percent, and with a few spiders (1 percent) 
account for the rest of the animal food. 

Vegetable food. — The vegetable portion is made up almost entirely 
of seeds, of which a majority are those of conifers, as was to be 
expected from the habits of the bird. 

Two other species of nuthatches, the slender-billed (Sitta c. 
aculeata) and the red-breasted {Sitta canadensis) occur in California. 
A few stomachs of each have been examined and the contents found 
to agree substantially with the foregoing. 

SUMMAEY. 

In conclusion, it may be said that, like other genera of the Pari (he. 
nuthatches are eminently useful birds. They do not prey upon culti- 
vated crops, cat but few useful insects, and probably are among our 
most efficient conservators of the forest and of the orchard. 

PLAIN TIT. 

(Bwolophus inomatus.) 
(Plate V.) 

The plain tit, like the rot of it> family, is quiet and unobtrusive, 
attracting little notice by its voice and movements, and probably is 
the mosl modestly dressed of them all. While it seems to prefer to 
hunt on oak-, it docs not neglect fruit trees, and often may be seen 
flitting about the orchard. 

The general character of its food is the same as that of other small 
arboreal -pern-. The relative proportions consumed, however, 
differ somewhat from those taken by other members of the family. 
The plain tit cat- a greater proportion of vegetable food than any 
other titmouse SO far a- known, and. what i- more remarkable. ;i 
Large part of this consists of the pulp of fruit. 



Bull. 30, Biological Survey U 



Plate V. 




Plain Titmouse i Baeolophus inornatuS' 



NUTHATCHES AND TITMICE. 69 

The following brief account of the food of this bird can be con- 
sidered only preliminary, as but 76 stomachs were available for exam- 
ination. These, however, are distributed through the year, so that 
every month is represented by at least three. While these results may 
be modified by future investigation, they probably afford a fair 
general idea of the yearly food of the species. 

Animal food. — Unlike most of the titmice, the plain tit eats less 
animal than vegetable food, the proportion being 43 percent of animal 
to 57 of vegetable. Examination of a greater number of stomachs 
may modify these figures but probably will not reverse them. The 
animal food is quite evenly divided among a number of elements, but, 
as with the bush tit. bugs (Hemipter a) appear to be the favorite, 
mostly eaten during the summer months. These amount to 12 
percent of the food. This is a little more than one-fourth of the 
amount of Ilemiptera eaten by the bush tit. The black olive scale is 
a prominent element of this part of the diet, and forms nearly 5 of 
tin' VI percent. In the month of August nine stomachs were taken, 
and 34 percent of their contents consisted of these scales, while one 
stomach was filled with them. The plain tit probably eats this insect 
more or less throughout the year, bttt the limited number of stomachs 
tinder consideration does not warrant a positive statement. The other 
hemipterous food consists of representatives of several families, such 
as leaf-hoppers (Jassidae), jumping plant-lice (Psylliclse), tree-hop- 
fpers (Membracidae), and other remains not identified. 

Lepidoptera, represented mostly by caterpillars, are the next 
baost important ingredient of the food. They amount to nearly 11 
percent, and are mostly eaten during the warm months, though one 
stomach taken in March was filled with caterpillars and one moth. 

Beetles (Coleoptera) are next in importance in the food, of Avhich 
they form nearly 7 percent. All are harmful species, but the mem- 
ber^ of one family are especially interesting. The genus Balaninus 
is composed of weevils in which the snout attains its greatest length, 
and sometimes is as long as the rest of the body. The insects, by 
means of this long snout, bore into nuts and acorn-, wherein they de- 
posit eggs, which hatch grubs that eat the nut. The tit finds these 
beetles while foraging upon the oak-. One stomach contained the 
remains of 13 of them, another 11. a third 8, and a fourth 7. while 
other- contained fewer. The plain lit feeds upon mast to some extent, 
and it is interesting to note that some of the stomachs which held 
remain- of Balaninus contained acorn meat also, showing that the 
bird- found the one while foraging for the other. 

Hymenoptera in the shape of nut- amount to nearly I percent, 
while wasps make up the total of this order to about 6 percent. 



70 BIEDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

Other insects aggregate a little more than 5 percent. Tipulid flies 
(daddy-long-legs) were found in several stomachs, as were grass- 
hoppers also. One stomach contained the remains of 13 of the latter, 
a remarkable number for so small a bird, but the bulk was not great, 
and they were probably the debris of several meals. Spiders are 
a very constant article of food, but do not appear in great numbers. 
as the average for the year is somewhat less than 1 percent. 

Vegetable food.- — In the vegetable food of the plain tit, fruit 
amounts to nearly 32 percent. Fruit is a rather surprising item of 
the food of this bird, as no one, so far as the writer can learn, has 
ever accused it of destroying fruit. The quantity is three times as 
much as is eaten b} r the linnet, and is another illustration of the fact 
that in estimating the status of a species the number of individuals 
as well as the amount eaten by each individual must be considered. 
The fruit consumed appears to be of the larger cultivated varieties, 
as no seeds of wild berries were found. 

Cherries were identified in a number of stomachs, and pulp of the 
larger fruits was abundant. As considerable of this was contained 
in stomachs taken in the late fall and winter months, it is evident 
that it was refuse left on the tree and of no value. Not only does the 
plain tit eat fruit, but to some extent it indulges also in grain. Oat.-; 
were found in a number of stomachs and constituted nearly 30 per- 
cent of the contents of two stomachs taken in January. Grain is 
probably- not eaten to any considerable extent, however, as the amount 
for the year is but little over 1.5 percent, and oats was the only variety 
identified. Leaf galls, seeds of poison oak, weed seeds, unidentifiable 
matter and rubbish make up the remainder, 24 percent, of the vege- 
table food. Xone of these are of much economic importance, except 
that the distribution of poison-oak seed is a nuisance. 

SUMMARY. 

From this somewhat imperfect review of the food of the plain tit 
it is evident that in its present numbers it is useful. The insects it 
eats are practically all harmful and the scales exceedingly so. More- 
over, its habit of foraging in trees enables it to capture some of the 
worst enemies of fruit and renders its work in this direction invalu- 
able. On the other hand, it eats quite a large percentage of fruit, 
most of which appears to be of cultivated varieties, and should the 
bird ever become as abundant a- the linnet now is it would undoubt- 
edly be a pest. This contingency, however, is extremely unlikely. 

( III>t\ i r-SIDED CHICKADEE. 

i Parus rufescens subspp. I 

While this bird at present inhabits mountain regions rather than 

orchards, -till it may not be out of place to give a short digest of our 



NUTHATCHES AND TITMICE. 71 

knowledge of its food. Fifty-seven stomachs were available for 
examination, and these were taken in every month of the year. 
except March. April, and May. The food consisted of nearly 65 
percent of animal matter and 35 of vegetable. 

Animal food. — Caterpillars constitute I s percent of the animal 
portion. They were found in nearly every month in which stomachs 
were taken, there being a fairly good percentage even in January and 
December. The greatest amount. 53 percent, was eaten in August. 
Hemiptera, consisting of leaf-hoppers, tree-hoppers, and olive and 
other scales, constitute the most important item of food, and amount 
to about 25 percent. These were found in all except two winter 
months. Wasps were eaten to the extent of L3 percent of the food, 
hut no ant- were found. Beetles amount to less than 2 percent of 
the food, but nearly all are noxious: weevils appeared in one stomach. 
Flies and grasshoppers are conspicuous by their absence, and not 
even a trace 1 of one was discovered. Spiders are a very constant ele- 
ment of the food of nearly all the titmice. In that of the chestnut- 
side they amount to nearly 7 percent for the year, though in August 
they constitute nearly 16 percent. 

Vegetable food. — The vegetable portion of the food consists of 
fruit pulp 8 percent, seeds nearly 20 percent, and miscellaneous mat- 
ter 7 percent. Fruit pulp was found only in a few stomachs taken in 
the fall and winter and was probably waste fruit. The seeds eaten 
were mostly those of coniferous trees, as was to be expected of a bird 
which spends so much of its life in evergreen forests. The miscel- 
laneous items of the vegetable food are leaf galls, bits of moss, and 
rubbish. 

SUMMARY. 

The above sketch of the chestnut-sided chickadee, while very 
imperfect, suffices to show the general character of its food. A few- 
stomachs also of the mountain chickadee (Paras gantbeli) have been 
examined and the contents found to agree in a general way with the 
food of others of the group. 

WREN TIT. 

{Chamaea fasciata subspp.) 

This modest, secretive bird, like the eastern chatj is more often 
heard than seen. At present it does not often live in orchards and gar- 
dens, and when it visits these it sticks closely to hedges and the denser 
parts of the shrubbery. In general it keeps to its original abiding- 
places in the dense chaparral of canyons and hillsides. So long as it 
is confined chiefly to these situations it- food habit- will never be of 



C2 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

more than secondary importance, but as cultivation spreads the bird 
will be forced more and more to reside in cultivated districts. 

The number of stomachs available for examination is 165, and as 
they represent every month except July the}' afford a fair idea of the 
salient features of the bird's yearly food. Of this 52 percent i 3 
animal matter, insects and spiders, and 48 percent of various vegetable 
substances. 

A ni mal food. — The most important item of the animal food con- 
sists of ants and wasps (Hyinenoptera), which amount to 23 percent 
of the whole. This is in strong contrast to the bush tit, whose diet 
contains scarcely any of these insects. About half of the Hyinenop- 
tera are ants. This is exactly what might be expected of a bird of 
such terrestrial habits and one so given to lurking under bushes and 
about deca}^ed logs and rubbish. The other insects of this order 
are small wasps. Beetles, collectively, the next most important item 
of food, amount to about 10 percent. The only useful species iden- 
tified were a few ladybirds (Coccinellidse), and a separate account of 
these was kept in order to estimate the harm done by their destruc- 
tion. The result shows that the diet of the wren tit contains less than 
1 percent of these useful beetles. The remaining beetles belong to 
various families, all of them harmful to vegetation. Caterpillars 
constitute a little less than 8 percent of the food, and are a very con- 
stant element of the diet. They appear to be eaten at all seasons, but 
in the early summer they amount to about one-fourth of the food. 
Quite a number of cocoons of tineid moths also were present in the 
food. 

Bugs (Hemiptera) are eaten to the extent of about 7 percent of the 
animal diet. In this respect the wren tit differs from the bush tit, 
over 44 percent of whose food is made up of these noxious insects. 
In one particular, however, the two birds are alike; scale- (Coccidae) 
are prominent in the food of both. The black olive scale {Saissetia 
olea ) and the greedy scale (Aspidiotus rapax) were identified in the 
stomachs of both birds, and many not specifically identified were 
found. The scales were probably obtained from orchards, as it is 
not likely that these insects have spread to wild plants and forest 
trees. As scales are to be had at all' seasons they are a constant 
element of the food of tits. The remaining animal food, les S I hah 
5 percent, is composed of various insects and some spiders. One 
stomach contained the legs of a grasshopper and another the remains 
of a wood-cricket. These are the only orthopterous remains in any 
stomach. Flies (Diptera) were eaten very sparingly. Spider- ap- 
peared in a great many stomachs but not in large numbers. They 
amount to a little less than 2 percent of the food. In one stomach 
were found 26 mites, commonly parasitic on beetles and other insects. 
Their hosts had probably been eaten by the tit. 



N il HATCH ES A.ND TITM UK. 73 

Vegetable /'"'" / . The vegetable contingent of the food. t8 percent, 
is made up of various substances, but ma\ be arranged in three cate 
gories fruit, poison-oak seeds, and other vegetable matter. Fruit, 
identified by seeds, pulp, and skins, amounts to a little more than 20 
percent of the \\ hole food. l-Vw direct complaints, however, have beeu 
lodged against the wren tit on the score of damaging fruit, and yet 
this record is nearh twice that of the linnet the bird against which 
the heaviest charges arc made by the orchardist. The reason for 
this difference is probably not far to seek. There are undoubtedly 
g hundred linnets in California to one wren tit. This again illus- 
trate- the point before made, that the mischief done by birds usually 
results from a superabundance of the individuals of a particular 
species, all uniting simultaneously to attack some particular product. 
Moreover, the fruit consumed by the wren tit consists largely of wild 
variet iei — such as elder berries (Sambucus), snow berries ( Symphori- 
carpos), coffee berries (Rhamnus), twinberries (Lonicera involu- 
crata) : and other- of a similar character. Seed- of blackberries or 
raspberries (Rubus) were found in a few stomachs, hut these may 
have been either wild or cultivated. 

A- the seeds of poison oak (Rhus diversiloba) occurred in many 
stomachs a separate account of them was kept. From August to 
February, inclusive, they form a constant and important (dement of 
the diet. For these seven months they constitute more than one- 
fourth of the food, and the average for the year is over 1<> percent. 
It seems natural enough that the wren tit should eat these seeds, as 
they are abundant and easily accessible. The fact is to be deplored, 
however, as they are not destroyed in the stomach, but either pass 
through or are regurgitated in condition to germinate. The seeds 
apparently are eaten for the sake of the rather thin layer of dry white 
pulp that surrounds them. Nfo doubt this is ver}^ nutritious, as in 
winter poison-oak seeds are a common article of diet for many species 
of bird-. The rest of the vegetable food, over 11 percent, is made up 
of a few weed seeds, leaf galls, and rubbish. Xone of it has special 
economic significance. 

FOOD OF YOUNG. 

Among the stomachs examined were those of a brood of 5 nest- 
lings about two week- old. and therefore nearly ready to leave the 
nest. The results are of interest a- showing that the wren tit fol- 
low- the usual rule and feeds it- young entirely on animal food. 
The largest item is caterpillar-, which amount to 63 percent of the 
contents. Spiders, with their cocoons and eggs, are next in import- 
ance, with 15.6 percent. Bugs, mostly leaf-hoppers, form 12.2 per- 
cent. Beetles of the May-beetle family, with a trace of eggshell, 



74 BIEDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

make up the remainder. 9.2 percent. One can not fail to notice the 
soft nature of most of this food provided for the young. The beetle- 
are the only exception, and these were the smallest item. 

SUMMARY. 

In summing U p it is evident that so far as its natural food is con- 
cerned the wren tit does little or no harm, as coccinellid beetles, the 
only really useful insects it eats, are consumed very sparingly. Its 
vegetable diet presents two points for criticism. It eats a moderate 
amount of fruit, and were the bird as abundant as the linnet the harm 
it would do in orchards would perhaps more than counterbalance the 
good. The wren tit, however, naturally is a denizen of dense shrub- 
bery, and as this is cleared away for farms and orchards the specie- 
is likely to diminish in numbers rather than increase, unless its habits 
radically change. The consumption of the seeds of poison oak is an 
unfortunate habit, since it aids in the dissemination of this poisonous 
plant, already too common and widespread. All things considered. 
the wren tit for the present is to be classed as beneficial. 

CALIFORNIA BUSH TIT. 

(Psaltriparus minimus calif ornicus.) 

(Frontispiece.) 

The bush tit is one of the smallest species of the family, and 
although its name implies that it is partial to bushe>, it more often 
is seen in large oaks and frequently on the tops of the highest trees. 
It shows the same indifference to the presence of man as the rest of 
the family, and frequently may be observed scrambling over orchard 
trees in search of its favorite food and paying no attention to the 
observer. That it does not prey upon fruit to an appreciable degree 
appears from the fact that less than 1 percent of its food for the year 
consists of fruit. Insects that live on trees, however, constitute 
four-fifths of its food, and most'of these are harmful. 

In the investigation of the food of this bird 353 stomachs were 
examined. They were collected in every month of the year, although 
April is represented by but a single one and March by only six. The 
greater number were taken during the growing months, when fruit 
and grain abound, and the fad that in these months the bird ate 
almost none of these products speaks volumes in its favor. The first 
analysis of the food of the year give- nearly 81 percent animal mat- 
ter, composed entirely of insects and spiders, to 1 ( .» percent of vege- 
table. A> the bush tit inhabit- the same range during the year, 
monthly variations in the kind and proportion- of food are only 



N [JTHATGHES AND ill M ECE. 75 

such as seasonal changes necessitate, and as these do not largely 
affect insects, which constitute the greal bulb of the bush tit's food, it 
follows thai the variation in diet from one month to another is not 
great. The smallest quantity of animal food was in March, when 
it amounted to 53 percent, but the percentage was almost exactly the 
-Mine for November. One stomach taken in April contained nothing 
but insects and spiders, and 11 collected in June contained no vege 
table food. Probably examination of a greater number collected in 
these months would result differently. While the material available 
for the present investigation is not so extensive as could be desired, it 
is sufficient to indicate beyond reasonable doubt that the relative pro- 
portions of animal and vegetable food in the diet of the bush tit vary 
little from season to season. 

Animal food. -The largest item in the insect portion of this bird's 
food consists of bugs (Hemiptera), which amount to over i I percent 
of the whole. The gnatcatchers arc the only birds yet investigated 
whose diet is made up so largely of this order of insects. Moreover, 
the particular families of Hemiptera so extensively eaten by the hush 
tit are the two that are most destructive to the interests of horticul- 
ture namely, the plant-lice (Aphididse), and bark-lice, or scales 
(Coccidae). The last amounts to nearly L9 percent of the year's food, 
and are eaten in every month. The greater number are consumed in 
July. In - percent; dime follow- second in rank, when they constitute 
33 percent of the food of that month. The large black olive scale 

$ Isst tia olece) was identified in 4-1 stomachs, but other species also 
were found. The question is often asked, Does any bird feed upon 
the San An-i- scale \ While the writer is not prepared to give a posi- 
tive affirmative answer from direct evidence; there can be no reason- 
able doubt that this insect is often eaten by birds. It must be borne 
in mind, however, that the so-called San Jose scale is one of the 
smaller -pe<-i'-. and it- distinctive characters are so minute that after 
it ha- been taken into a bird's stomach, mixed with other food, and 
more or less digested, it is impossible to determine its identity. It 
is easy to ascertain that a pasty ma— in a bird's stomach is composed 
of scales partly digested, but to identify the species is quite another 
matter. The olive scale and other- of ii- genus, on the other hand, 
are so large and their -hell- are of such structure that they can often 
be identified, at least generically, even from fragments. 

While the San Jose scale was not positively determined, another 
species of the same genus, the greedj scale (Aspidiotus rapax), was 
found in 1 stomachs, and scales not specifically identified were found 
in 11."). Of a total of 353 stomachs, L58 held scales; several were 
entirely filled with them, and in quite a number upwards of 90 per- 
cent of their contents consisted of these insects. No other family of 
insects was identified in so many stomachs. AlS it is certain that the 



tb BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

food contained in a bird's stomach at a a"iven time is only a fraction 
of the daily consumption, we may infer that not many days pass in 
the life of a bush tit when it does not eat a considerable number of 
scales. 

Before leaving the subject it may be well to add a few words on 
the economic relation- of scale-insects in order that the value of the 
work done by the bush tit may be fully appreciated. Mr. Marlatt 
says : 

The most destructive insect enemies of fruits in California are undoubtedly 
the scale insects, few if any other insects, aside from the grape Phylloxera, at 
all approaching them in this respect. Of these, the ones of greatest moment 
and in the control of which vast sums of money are expended are the black 
scale, the red scale, and tbe San Jose scale. For the olive and citrus plants 
the black scale is the most important, and for the deciduous plants the San 
Jose scale takes similar rank." 

When the immense number of bush tits and other birds in Califor- 
nia that eat scale insects is considered, it becomes evident that the 
aggregate of these pests annually destroyed by them must be enor- 
mous. It may be urged that despite the attacks of birds, scales have 
caused, and still are causing, much damage to fruit trees, and that the 
work of birds alone is inadequate to save the trees from destruction. 
This is undoubtedly true, but it must be remembered that the birds 
are confronted with abnormal conditions. The great and rapid 
development of the fruit-growing industry on the Pacific coast and 
the simultaneous and widespread introduction of several new species 
of scales resulted in a sudden increase of these pests, while their ene- 
mies, the birds, enjoyed no such opportunities for increase. In time. 
no doubt, an equilibrium would have been reached, and birds would 
have played an important part in establishing this by exerting a con- 
stant and steady check upon the increase of scales. Unaided, how- 
ever, their numbers are too few to cope with the insects which, under 
favorable conditions of climate and environment and unmolested by 
other natural insect enemies, multiply to countless myriads. 

The remaining portion of the hemipterous food of the bnsh tit. 
over 31 per cent, is made up of plant-lice, tree-hoppers (Membracidae) . 
leaf-hoppers (*Jassida3), some jumping plant-lice (Psyllidse), and a 
considerable number of false chinch bugs (Nysius angustatus), with 
a few lace-bugs (Tingitidae). Of the plant-lice little need be said. 
As pests to vegetation their reputation is world-wide. No pari of a 
plant is free from attack. They infesi Leaves, trunk, and root-, and 
some of their legions of species prey upon nearly every kind of land 
plant. They arc a frequenl element of the food of the tit. but as their 

a Insecl control in California, by C. L. Marlatt, l. s. Dept. <>i' Agriculture, 
yearbook, L896, \>. 220. 



NUTHATCHES AND nTMICE. I I 

bodies are of the softesl texture specific identification is not possible. 
Many of them, however, were determined to be of the species com 

inonlv called '\\()oll\ aphides,' a- their bodies are covered with ;i 
white cottony «M- woolly substance. A.phides were identified in 30 
stomachs, but ii is probable thai they were contained in more, a- a 
pasty mass thai could only he called 'hemipterous remains 1 was of 
frequent occurrence. Leaf-hoppers were found in manj stomachs, 
ami appear to be favorite food. Tree-hoppers also arc eaten to a con 
siderable extent, and a- then- bodies are hard, like those of beetles. 
they are more easily recognized than plant lice. The jumping plant 
lice were found in a few stomachs, Ian were rather difficult to dis 
tinguish in the conglomeration of plant-lice and other soft-bodied 
insects. False chinch bugs were found in a number of stomachs 
from the southern part of the State. These, perhaps, were the best 
preserved of any of the insects, for in most cases they could he dis- 
tinguished individually. Over 50 were taken from one stomach. 

Next to the bug family, the favorite food of the bush tit- seems to 
he hectic-. They constitute somewhat over 1<> percent of the year's 
food and attain their maximum in September, when they amount t<> 
a little more than 27 percent of the food. The fewest were taken in 
December — less than 1 percent — hut in all the other months they were 
found to a moderate extent except in the one stomach taken in April. 
which contained none. Among them were >peeies of the ladybug 
family (Coccinellidse), which are useful insects, a- they are mostly 
carnivorous and feed largely upon plant-lice. In order to ascertain 
just how much harm the tit does in devouring ladybugs. a separate 
account was kept, and it was found that the total amount eaten dur- 
ing the year was 2. 1 percent of the wdiole food. Most of these insects 
were eaten in September and October, when the consumption 
amounted to 11 and »', percent, respectively. These are the only 
decidedly useful insects eaten by the hush tit. and in view of their 
-mall uumber the subject may he dismissed without further com- 
ment. The other hectic- taken were largely small leaf-beetles (Chrys- 
oinelida'). all of which are harmful. With them were some small 
weevils (Rhynchophora), which \'cvi\ upon seeds and other parts of 
plants, with a few scolytids that burrow under the hark of tree- to 
their great injury. 

Butterflies and moth- (Lepidoptera), most of them in the larval 
form (caterpillars), are next to hectic- in importance in the food of 
the bush tit. They are. however, far from being such favorite food 
a- bugs. The total i- a little more than 16 percent. They are fairly 
evenly distributed through the year, though in spring and early sum- 
mer they are consumed t«> a somewhat larger extent than in fall and 
winter. Thegreatest consumption was in May. when they aggregated 



78 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

nearly 69 percent. Lepidoptera in the adult form do not as a rule 
constitute an important part of the diet of birds, but. with the excep- 
tion of the flycatchers, the titmice perhaps eat the most. The greater 
number consumed by these insects, however, are eaten as larva*— cat- 
erpillars. A few. however, are eaten in the pupa state, and here the 
bush tit has a good record. In a number of stomachs were remains 
of the pupae of the codling moth, one of the worst pests to the apple 
industry. This insect is protected from the attacks of birds by its 
peculiar mode of life. It passes the larval stage inside the apple. 
The adult moth flies mostly by night and hides during the day. 
When the larva is full grown it leaves the apple and seeks a place of 
concealment, such as a crevice in the bark of the tree, a crack in the 
trunk, or among rubbish on the ground, where it changes to a chrys- 
alis. It is in this stage that the insect is most vulnerable to the 
attacks of birds, and as the whole family of titmice get most of their 
food by searching in just such places as those used for concealment by 
the larva, it is not surprising that they find and devour many of them. 

The cocoons of certain tineid moths are a very constant, though not 
large, component of the food of the bush tit. The larva3 of many of 
the Tineina are leaf -miners, and therefore injurious when attacking 
economic plants. 

Strangely enough, wasps and ants (Hymenoptera) are nearly absent 
from the food of this bird. The total amount for the } T ear is Less 
than H percent. In view of the fact that ants are always crawling 
over the trunks and branches of trees, the very places where the tit< 
feed, it seems strange that so few of them are eaten. Moreover, 
plant-lice always have ants in attendance upon them, and when tits 
eat so many plant-lice it is rather remarkable that they should not 
take some of the ants also, as do the smaller woodpeckers, whose food 
habits are in many respects so similar. In 353 stomachs only two 
ants were identified, one in the adult and one in the pupal stage, and 
these were in separate stomachs. In 17 other stomachs a few frag- 
ments of what probably were small wasps were found, which make up 
the total of the hymenopterous diet of the bush tit. 

The remaining animal food of this bird, about 8 percent, is com- 
posed of various insects, such .is a few flies, a few bits of grasshoppers, 
insects' eggs not further identified, with a considerable number of 
spiders. That the tits should not eai grasshoppers is not surprising, 
a- these insects do not commonly infest tree- where the birds feed, 
and as a rule they are rather large game for such -mall birds. The 
greal bulk of the s percent, however, consists of spiders, which con- 
stitute a constant item of food in every month. Quite a number of 
pseudoscorpions also were found in the stomachs, but, owing to their 
minute size, the percentage is not very noticeable. 



NUTHATCHES \M> I'M M [CE. 79 

Vegetable /' The vegetable food of the bush til ma\ be consid 

ered under two categories fruit and miscellaneous matter. Fruit in 
some form was found in stomachs taken in the months from A.ugust 
to November, inclusive. The average amount eaten in those four 
months was a little less than 1 percent. It is represented in the 
stomachs by pulp and skins, which have not been further identified. 
The miscellaneous vegetable matter is composed of a few seeds, gran- 
ules of poison <>ak (A7///.V diversiloba) , leaf galls, and rubbish. The 
seeds of poison oak are eaten by many birds, and so are distributed 
about the country, but, as a rule, they are too large to be swallowed 
by the tit. which content- itself with peek inn- off the wax surrounding 
the seed. This is identified in the stomachs by certain woody gran 
ules. A large portion of the vegetable food consists of small galls, 
apparently from leaves. They are eaten when first developed, when 
young and tender. A- each of these probably contained an egg 
or grub, it is questionable if they should not be classed as animal 
food. The remainder of the vegetable matter is of such a nature that 
the only term which ready describes it is ' rubbish.' It is probable 
that it is mostly taken accidentally along with other food, and perhaps 
should not be considered in the food category. 

FOOD OF NESTL1 NGS. 

Ajnong the :> ».'' ; > stomachs of the bush tits whose food lias been 
discussed was one brood of eight nestlings about ten day- old. A.s 
these are the only nestlings collected, their food would merit atten- 
tion, but examination shows it to be of unusual interest. The vege- 
table matter in these stomachs was only three-fourths of 1 percent 
and consisted of one seed and some rubbish. The animal matter 
comprised, approximately : Beetles 2, wasps 2, bugs 8, caterpillars and 
pupa- s <>. and spiders 7 percent. The point of greatest interest, 
however, lies in the fact that every one of these stomachs contained 
pupae of the codling moth, distributed as follows: Two stomachs 
contained 2 each, two contained 3 each, one contained 4. one 7. one 9, 
and one 11. making 11 in all, or an average of over 5 to each. The 
oak tree in which these bird- were found was in a belt of timber 
along a creek, and just across the stream was a considerable area of 
neglected orchard. It is evident that the parent bird- used this 
< rch'ard as a foraging ground and did their best toward remedying 
the neglect of the owner. A- with nestling birds feeding and diges- 
tion are almost continuous during the hour- of daylight it follows 
that the above record would be several time- repeated during a day's 
feeding. There were probably not less than a dozen nests of the 
bush tit (several were seen) along the border of this orchard, and 
i(. a- is probable, the occupants all did as good work a- the one- 



80 BIEDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

recorded it is evident that the birds must exert a powerful restrictive 
influence upon the increase of the codling- moth, as well as other 
insects. 

SUMMARY. 

In a resume of the food of the bush tit the most prominent points 
to be considered are the fact that four-fifths of its diet consists of 
insects and spiders, nearly all of which are harmful: that more than 
half of its animal food is limited to a single order of insects, Ilemip- 
lera: that it eats the particular families of this order which contain 
the worst of insect pests; that the vegetable contingent of the food is 
made up almost entirely of substances of no economic value. It is 
doubtful if more efficient checks upon the increase of many species 
of forest and orchard insects can be found than the titmice and other 
closely related species. Bush tits, therefore, are a valuable asset to 
the State of California and should be protected and encouraged in 
every possible way. 

Following is a list of insects identified in the stomachs of bush tits -. 

COLEOPTEKA. 

Grepidodera helxines. Scymnus nanus. 

Diachus auratus. Sfotoxus alamedw. 

Orthoperus sp. Anthicus sp. 

Corticaria sdssus. Apion vespertinum. 

Scymnus marginicollis. Deporaus glastinus. 
Scymnus pollens. 

HEMIPTERA. 

Nysius angustatus. Saissetia olccr. 

Geocoris bullatus. [spidiotus rapax. 



LEPIDOPTERA. 



Carpocapsa pomonella. 



The following families of Hemiptera were identified: 

Tingitidse. Psyllidae. 

( lapsidse. < !occid». 

Membracidse. Aphididse. 

J.issidse. 

KINGLETS. 

Kinglets, like ffnatcatchers and titmice, are small, active birds and 
spend most of their lives on trees. So nearly do the feeding habit- oi 
these diminutive arboreal species resemble each other that in winter 
n i- not unusual to see companies of titmice, kinglet-, creepers, and 

nuthatches all together, engaged in the same unending search for 



KINGLETS. 81 

food. When one notices how thoroughly each tree is inspected bv 
dozens of pairs of keen, prying eyes, he is surprised that any insects or 
their eggs should survive to produce broods. 

i;i B1 i ROM NED M NGLE I . 
i Regulua calendula, > 

The ruby-crowned kinglet is Known in California principally as n 
winter resident, though in some of the high mountains it remains 
through the summer and breeds. It- small size would prevent it 
from doing appreciable injury to fruit or grain were any to be 1 1:1 < 1 

when it i- in the fruit and -rain raising regions. 

A.s might be inferred from field observations, its diet consists 
almost entirely of insects and. their eggs, and the number it destroys 
is beyond computation. 

In investigating the food of the kinglet 294 stomachs were exam- 
ined, all taken in California from September to April, inclusive. 
Only 1 stomach was collected in September, 5 in March, and 5 in 
April. The other included months are fairly well represented. The 
food consisted of 94 percent of animal matter and 6 percent of vege- 
table. It was made up of insects, spiders, and pseudoscorpions — 
minute creatures resembling microscopic lobsters — fruit, weed seeds, 
etc. 

Animal food. — The animal food is quite evenly distributed through 
the season. The greatest amount. 100 percent, appeared in the first 
and last two month-, and the least, 79 percent, in January. Hyme- 
noptera, in the shape of wasps, and a few ants appear to be the 
favorite food, as they aggregate over 32 percent of the whole. The 
stomach taken in September contained none of them, but in every 
other month they are fairly well represented, and with but little 
variation until .March, when there is a Midden increase, which con- 
tinue- in April. This is undoubtedly due to the increased numbers of 
these insects following the return of warm, dry weather, for the order 
is noted for it- fondness for warmth and sunshine. Adverse criti- 
cism may be made upon this element of the kinglet's diet, as flying 
Ilymeiioptera are useful agents in the fertilization of flowers, and 
some species of plant- are dependent upon them for the performance 
of this important function. The parasitic species of this order also 
were found to -ome extent in the food of the kinglet, and unques- 
tionably many of these are decidedly useful. 

In the food of the kinglet, bugs (Hemiptera) are next in impor- 
tance. They constitute nearly 26 percent of the diet, and are found 
in greatest quantity in the first months of the bird's winter stay, in 
September and October, but gradually decrease till spring. 

9379 — No. :;i»— oT 6 



82 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

The following- families of Hemiptera were recognized in the stom- 
ach contents: Assassin-bugs (Reduviida?), lace-bugs (Tingitidse), 
leaf-bugs (Capsidae), leaf-hoppers (Jassida?), tree-hoppers (Membra- 
cida'). jumping plant-lice (Psyllidse), plant-lice (Aphididse), and 
scale-insects (Coccidae). Stink-bugs (Pentatomida?) . which are the 
most universally eaten by birds of any Hemiptera. are entirely want- 
ing. Evidently it was not lack of opportunity that prevented the 
kinglets from eating the last-named insects, for other birds collected 
at the same time and place had partaken of them freely. From the 
human point of view it is not strange that birds should reject them, 
for to us their odor is vile and their taste nauseous. It will be 
noticed that the Hemiptera selected by the kinglet are mostly species 
of small size, but happily they are the very ones that are the most 
harmful to the interests of man. The tree-hoppers, the leaf -hoppers, 
and the jumping plant-lice, when abundant, are pests, and often do 
great harm to trees and smaller plants, while the plant -lice and scale- 
insects are the worst scourges of the fruit grower — in fact, the preva- 
lence of the latter has almost risen to the magnitude of a national 
peril. As has been before pointed out, it is these small and seemingly 
insignificant birds that most successfully attack and hold in check 
these insidious foes of horticulture. 

Beetles of various families and species were eaten by the kinglet to 
the extent of 13 percent of the season's food. They belong to species 
that are more or less harmful, with the exception of a number of 
ladybirds (Coceinellida?), which from their habit of feeding on plant- 
lice are eminently useful. The damage done by the destruction of 
these useful beetles, however, is small, since they aggregate less 
than 2 percent of the whole food. Singularly, nearly all were in 
stomachs obtained in February. In this month 8 percent of these 
beetles were eaten, while in no other month was so much a^ 2 percent 
taken. Another curious fact is that almost all of these belong to the 
genus Scymnus, which is made up of minute black creatures which 
one might think would pass unnoticed by birds. On the contrary, 
the small and insignificant individuals of this genus appear to be 
eaten much oftener than the larger and more showy species. While 
the eating of ladybugs by kinglets or other birds is to be deplored, 
it must be acknowledged that little harm is done so long as the num- 
bers destroyed are as moderate as the above figures imply. 

Of the harmful beetles eaten the weevils are perhaps the most 
interesting. One stomach contained 20 individuals, which seems 
a large meal iii view of the size of the bird. Many of the weevils 
belong to the family of engravers (Scolytidse), which live under the 
bark of tree- and are forest pests. Another beetle found in many 
stomachs is Notoxus alamedce, an insect that lives on trees, but which 
does no harm so far as known. One stomach contained the remains of 



KINGLETS. 83 

loo individual- of this species. Other beetles were found belonging 
to about a dozen families, all more or Less injurious. 

Lepidoptera, both larvae (caterpillars) and adult forms (moths 
and butterflies) constitute only a anal] portion of the kinglet's diet. 
They were eaten sparingh in everj month but one, but in all aggre 
gate <>nly 3 percent of the whole. While a few caterpillars were eaten, 
most of the lepidopterous food consisted ^\ the minute cocoon- of 
tineid moths, a family of immense size, wide distribution, and destruc- 
tive habits. They arc largely leaf-miners, and do much damage to 
the foliage of fruit and other trees. Thej are so small that even the 
little kinglet can eat a great many of them at a meal. In only 2 
stomachs was anything found that resembled a grasshopper, and in 
both the quantity was small and the identification doubtful. Mies 
i Diptera I constitute nearly 17 percent of the diet, but are very une- 
venly distributed. The greatest amount in one month was in Janu- 
ary, ;> >~> percent, all of which was in 7 stomachs collected in the same 
place within three day-. These 7 stomachs contained an average of 
96 percent of dipterous remain-. The birds evidently found a 
gathering of flies, probably dormant, and Idled themselves almost 
exclusively with them. Another -cries of I. taken at the same place 
in February, also had eaten Hie- to the extent of over 80 percent of 
the food. Spider- and pseudoscorpions amount to nearly -J. percent 

of the f I. and are taken quite regularly through the season, though 

the greater number were eaten in October. These last are curious 
minute creature-, the various species of which live under stones, on 
the hark of trees, and in old book-. 

Vegetable f<»><L — The vegetable food of the kinglets may be dis- 
cussed under three heads — fruit, weed seeds, and miscellaneous vege- 
table matter. Fruit amounts to less than 1 percent of the food, prin- 
cipally elderberries (Sambucus). Weed seeds are present to the 
extent of a little more than one-tenth of 1 percent, and may therefore 
he dismissed without fun her comment. In the miscellaneous vege- 
table food two item- include nearly the whole — seeds of poison oak 
and leaf galls — which together amount to somewhat more than I 
pei-cent. The eating of the seeds of poison oak i- not a commendable 
habit in any bird, for the seeds are not destroyed, hut after the wax 
on the outside i- digested are either passed through the intestine or 
disgorged, and so these harmful plant- are disseminated. In many 
of the stomachs certain -mall round bodies were found that were 
diagnosed a- • leaf nail-.' They appear to he galls in the early stage 
and are eaten while -mall and tender. 



The foregoing discussion of the food of the ruby-crowned kinglet 
serves to confirm popular opinion with regard to this bird. A- it- 



84 



BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 



food consists so largely of insects and as these include so small a per- 
centage of useful kinds, the kinglet must be classed as one of the 
most beneficial of birds. To the horticulturist it is especially valu- 
able, as nearly all of its food is obtained from trees. With respect to 
the persistency with which it forages among trees, it differs conspicu- 
ously from such aboreal species as leave the trees in midsummer to 
feed upon grasshoppers. 

WESTERN GOLDEN^- CROWN KINGLET. 

(Regulus satrapa olivaceus. I 

Another kinglet, the western golden-crown, occurs sparingly in 
winter in some parts of California. Only 9 stomachs have been 
examined, but these in the nature of their contents are so similar to 
those of the ruby-crown that statements applicable to the latter are 
almost certain to apply as well to this species. Xo vegetable matter 
was found in any of the 9 stomachs, and the insects belong to the 
same orders and were taken in essentially the same proportions as by 
the other species. 

Following is a list of beetles which were identified in the stomachs 
of the two kinglets : 



Goccinella i. californica. 
Adalia frigida. 
Scymnus pal lens. 
Scymnus nebulosus. 
Hi speroba nus abbreviatus. 
(Jorticaria ferruginea. 
Throscus St rictus. 
Lisinis intemiptus. 



Aphodius rugifrons. 
Diachus an rat us. 
Crepidodera helx-ines. 
Epitrix- parvula. 
Notocous alumedw. 
Anthicus nitidulus. 
Apion r< spertinum. 
Pityophthorus pubipennu 



Beetles were identified as belonging to the following families 



Staphylinidse. 

( Joccinellidse. 

Monotomidse. 

Lathridiidse. 

Elaterida?. 

Throscidse. 

Lampyridse. 

Malachiidse. 



Scarabseidae. 

( Jhrysomelidse. 

Tenebrionidse. 

Anthicidse. 

Curculionidse. 

Scolytidse. 

< Mhcr Ethynchophora. 



GNATCATCHERS. 
( Polioptila spp. i 



Gnatcatchers are small, active birds of modesl color- and unob- 
trusive notes. While not conspicuous, they are none the Less deserv- 
ing of respect and consideration. No complaints have been made 
thai these busy creatures ever injure fruit <>r other crops. Their food 



<;.\ \ k \ i«iii RS. 85 

is composed almosl exclusively of insects, which t hey hunt with untir- 
ing energy from morning til] night. Like the titmice and kinglets, 
gnatcatchers arc fitted by nature to perform a service which larger 
species arc unable to accomplish. There are hosts of minute insects, 
individually insignificant but collectively a pest, thai arc too small 
to be attacked by ordinary birds and are to be combated by man. if at 
all. only at greal expense. Ii is to so deal with such pests thai they max 
not unduly increase thai these tiny birds would seem to be especially 
designed. Three species of gnatcatchers live within the limits of the 
State of California. Two of them, Polioptila plumbea and P. cali- 
fomica, arc confined to the southern pari . while the third, /'. ccerulea 
obscure occurs locally throughout the State. The materia] for a 
thorough discussion of the food of these birds is unfortunately nol at 
hand, bul there is enough to show conclusively the nature of the 
work they are doing, and to enable us to assign them their proper rank 
among the friend- and helpers of mankind. 

The food of the gnatcatchers is remarkably constant in character 
throughout the year, varying bul little from month to month. It is 
probable thai these birds have a preference for a certain diet, and 
search till they find it. 

Only 30 stomachs of P. c. obscura and the same number of P. cali- 
fomica have been examined, and their contents were so similar that 
they may be treated as from a single species. 

Vegetable f<><><l. — Of the 60 stomachs three only contained any 
vegetable food whatever, and in only one did it amount to a respect- 
able percentage. This one held 92 percent of seeds of some species 
of Rhus; another contained 8 percent of unknown seeds, and the 
third a lew hit- of rubbish, which amounted to only 2 percent of 
the whole contents. The total vegetable matter in the (JO stomachs 
aggregated less than 2 percent of the entire food. 

Animal food. — The remainder of the food, over 98 percent, is made 
up of hectic-, wasps, bugs, and caterpillars, with a few flies, grass- 
hoppers, and spiders. Bugs (Hemiptera) constitute more than half 
of the whole food. 64 percent. These belong to the families of stink- 
bugs ( Pentatomidse), shield-bugs (Scutelleridse), tree-hoppers (Mem- 
bracidaa), leaf-hoppers (Jassidae), and leaf-bugs (Capsidaa), with 
perhaps trace- of several other-. In one stomach were 20 percent of 
black olive scales (Saissetia oleo ). All of these are harmful to trees 
and other plant-. Wasps and a few ant- (Hymenoptera) are next 
in importance a- an elemenl of the gnatcatcher's food, and amount 
to over 16 percent of the whole. These birds, like the flycatchers, 
take much of their prey on the wing, and it i- probable thai wasps 
and -mall bees are captured in this way. Beetles of several families 
were eaten to the extent of over 7 percent of the food, hut no decided 



86 BIEDS OF CALIFORNIA AFFECTING FEUIT INDUSTRY. 

preference for any particular kind is indicated. The only decidedly 
useful insects in any of the stomachs were 2 ladybird beetles (Co'c- 
cinella t. cdlifornica), which had been eaten by P. califomica. As 
this beetle is very abundant in California it is not surprising that 
birds should eat a few of them. Caterpillars amount to about 5 
percent of the diet of the gnatcatchers. Apparently they are not a 
favorite food. Other insects, such as a few flies and grasshoppers, 
with some spiders, aggregate 6 percent, and probably are makeshifts, 
eaten when nothing more palatable is at hand. 

SUMMARY. 

While the foregoing discussion of the food of the gnatcatchers is 
based upon a small amount of material, the agreement of the evidence 
renders it probable that a much larger quantity would not greatly 
change the results. This evidence confirms what has long been sus- 
pected, that the gnatcatchers are doing a useful work and should be 
carefully protected. 

RUSSET-BACK THRUSH. 
(Hylocichla ustulata.) 

The russet-back thrush abounds in the region about San Francisco 
Bay and other parts of the humid coast belt. It remains in this part 
of the State from April to November,, inclusive, and then moves 
farther south for the winter. Its favorite haunts are the bushes and 
trees bordering streams, and in these it nests and rears its young. 

TThile the thrush is very fond of fruit its partiality for banks of 
streams keeps it from frequenting orchards when they are far from 
water. It is most troublesome during the cherry season, at the time 
when the young are in the nest. It might be inferred from this that 
the nestlings are fed on fruit, but such is not the case to any notice- 
able extent. The parent birds eat the fruit themselves, while the 
young, as is usual with nestlings, are fed mostly upon insect-. The 
old birds eat some fruit throughout the season, but do not seem to 
attrad much attention by their depredations on prunes and the later 
fruits. As the thrush, unlike the linnet, i- one of the so-called • soft- 
billed * bird-, it- attacks on fruit are limited to the thin-skinned varie- 
ties. Probably it can peck holes in ripe cherries; Mill it i- as often 
-een on the ground pecking at fallen fruit as attacking the fruit on 
the trees. It thus probably confines it- depredations upon the later 
fruits to such a- have already been broken into by linnet- or other 
-tout-billed birds. 

Be this a- it may. the thrush i- an edicient destroyer of insects, 
and during the eight month- of it- sojourn in the fruit region a 
little more than half of its food consists of harmful insects. In the 



c\ \ ^CATCHERS. 87 

investigation of this bird's diet L57 stomachs were examined. The 
birds came from various points about San Francisco Bay, and on the 
coast from Monterey to Santa Cruz, except one migrant which was 
taken in the southern part of the State. Onlj 6 stomachs were 
collected in April. 5 in October, and 7 in November. In the remain- 
ing Tour months L39 were taken, and as they are fairly evenly dis 
tributed the results for these months may be looked upon as reason- 
ably reliable. Examination of the food shows 52 percent of annual 
matter to I s percent of \ egetable. 

. I nimal food. The greatest quantity of animal food was eaten in 
the first ami last pan- of the season -in fad. the six st achs col- 
lected in April contained no trace of vegetable food. The animal 
matter decreases in each month up to September, in which month 
only 17 percent was eaten. From this month it increases, and ends 
with 62 percent in November. Too much reliance should not be 
placed upon the latter figures, a- they were obtained from entirely 
too few stomachs, and are likely to he modified by the examination of 
more material. The animal portion of the food is mostly insects and 
spiders, with some earthworms and sowbugs (Oniscus). 

Useful beetle- (Carabidse, Coccinellida?, etc.) amount to less than 
'■\ p<i vent of the food of the year. Most of them are eaten at the 
beginning of the season before other insects are common. Other 
hectic-, all more or less harmful, constitute 11 percent of the year's 
food, and ire eaten chiefly the first of the season, decreasing towa.nl 
fall hut with a slight increase at the end. They are pretty evenly 
distributed among the more common families, and no decided prefer- 
ence i> evident for any. It is probable that the thrush eats any 
beetles that come iii its way. and does not make special effort to find 
a particular kind. 

Caterpillar- form somewhat more than 8 percent of the food, and 
while they are eaten in every month of the thrush's stay, they are 
taken much more freely previous to August. During and after that 
month they cease to he an important element of the diet. The average 
consumption of the first four months of the season is a trifle over 15 
percent. Ant- and wasps (Hymenoptera), bugs (Hemiptera), flies 
(Diptera). and grasshoppers (Orthoptera) are eaten by the thrush, 
although little preference is shown for any one of these except for 
Hymenoptera in the shape of ant-. These are eaten with remarkable 
regularity throughout the season, and form about 1<» percent of the 
food. This is the largest insect element in the food of the thrush, 
and the regularity with which ant- are eaten would seem to indicate 
that they are highly esteemed and especially sought for. 

While these insects do not often make themselves pests by directly 
attacking fruits and crops, they aid and abet the work- of other insects 
in a way which renders them a- bad a- the worst of those directly 



00 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

attacking crops. Their habit of caring for and protecting plant-lice 
is too well known to require extended comment. They take possession 
also of the empty burrows of wood-boring larva? and extend these 
galleries still farther into sound timber. They often throw up 
mounds on lawns and in gardens, where it is almost impossible to ex- 
terminate them. In houses they frequently are an intolerable nui- 
sance, infesting the pantry and spoiling food. The species that are 
not offensive in these various way- are mostly of a neutral character 
in their economic relations, and their destruction by birds does 
neither good nor harm. 

Hymenoptera, other than ants (mostly wasps), bugs, flies, and 
grasshoppers, with some spiders, amount altogether to 12 percent of 
the year's food, and appear very regularly through the season. Grass- 
hoppers, however, are near being conspicuous by their absence, as re- 
mains were found in only T of the 157 stomachs. This is rather re- 
markable for a bird whose habits are so terrestrial as those of the 
thrush. The majorit3 T of ground-feeding birds and many arboreal 
species feed largely upon grasshoppers. In fact, there is no order 
of insects for which insectivorous birds in general show such a decided 
preference. The spiders eaten by the thrush belong largely to the 
order Phalangida, commonly known as c harvest men ' or ' daddy- 
long-legs.' 

Vegetable food. — The vegetable food of the thrush consists prac- 
tically of fruit either wild or cultivated. A few weed seeds were 
found in several stomachs, but they amount to only a trace. It is 
probable that the greatest harm done by this bird is to the cherry 
crop, though undoubtedly it eats the later fruits to some extent. In 
May and June the fruit eaten reaches 41 and 38 percent, respectively, 
and this probably represents the greatest injury which the bird does, 
as most of the fruit was the pulp and skins of cherries. From June 
onward seeds of blackberries and raspberries (Kubus) were fre- 
quently found in stomachs, but as these berries are both wild and cul- 
tivated it is impossible to tell how much came from gardens. One 
stomach taken in early June contained seeds of the twin berry (Loni- 
cera involucrata) . Seeds of the elderberry (Sambucus) were abun- 
dant in stomachs taken in the late summer ami fall, and indicate that 
this fruit constitutes a very considerable portion of the vegetable diet 
of the thrush at that season. Besides these were seeds of the- pepper 
tree, of Solanuin (a weed), and one stomach contained fruit of the 
coffee berry (Rhamnus califomica). A few seeds of poison oak were 
found in two or three stomachs. The greatest amount of fruit was 
eaten in September, and reaches a total of over 80 percent, but as the 
number of stomachs i- not a- great a- could be desired the result can 
scarcely he considered final. Moreover, a large part of this was wild 
fruit. 



GNAT< \ I < HERS. 



89 



li K »D OF ^ ' >l NG 



Anions the stomachs examined were those of 25 nestlings taken in 
June and July. Their approximate ages and dates of capture are 
given in the follow ing table : 





Mali- Of 

taking. 


i Three .... 2 

2 Four 

i bree .... i 

1 hive .... 11 

i bree .... i 

rwo 3 

rwo ii 

8 Five 7 


.hill.' S 

June 8 
June 15 
June 19 
Julj 21 
Julj 

June 13 
July 16 



Taking the collection as a whole their stomachs contained 92.6 per- 
cent animal matter to T.I percenl of vegetable. Caterpillars aggre- 
gate nearly 27 percenl and were round in every stomach but 7. No 
other element was so abundant. Beetles collectively are next in 
importance, with 22 percent. ( )f these the useful Carabidse amount to 
7.7 percent and are very irregularly distributed. All the remain- 
der are more or less harmful species. Bugs (Hemiptera) aggregate 
13.8 percent. Five families of these were identified, viz., stink-bugs, 
leaf-hoppers, tree-hoppers, shield-bugs, and cicadas. Ants and a few 
other Hymenoptera amount to 12 percent, and spiders to exactly the 
same. These last were mostly harvest-men or daddy-long-legs (Pha- 
langidae). A few miscellaneous insects amount to 6 percent, which 
make- up the whole of the animal food. Four stomachs of the russet- 
back contained remains of grasshoppers and three of these were nest- 
lings. Carabid beetles were eaten bv the voung birds to the extent of 
7.7 percent, which is more than three times the amount eaten by the 
adult-. This is rather singular, for most of these insects are very 
hard-shelled and not at all the kind of food usually selected for young 
birds. Another interesting point is that all were contained in the 
stomachs of broods Nos. 2, I. and 5. None of the other nestlings' 
stomachs held a 1 1';'*' 1, of them. 

The vegetable food amounts to ,- >. s percent of fruit, with less than 
1 percent of two or three other things. The fruit was nearly all 
either blackberries or raspberries, which were found in 11 stomachs, 
with twin berries in 1. One seed of filaree and some rubbish made up 
the rest of the vegetable food. 

While the above affords a general idea of the food of these nest- 
lings as a whole, there are some di fferences in the food of the different 
broods, which may be worthy of notice. The stomachs of broods Nos. 
1, 2, and 6 contained no vegetable matter, as was the case with one each 
of broods 3 and 5. Broods 1, 7, and s had all eaten vegetable food. 



90 BIEDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

but more than four-fifths of the whole was contained in the stomachs 
of broods 7 and 8. The average percentage for these two broods was 
over 22 percent, or about three times that of the whole. Again, 
Hemiptera. in the stomachs of broods Xos. 1 to 7, inclusive, amount 
to an average of less than -1 percent, but in brood Xo. 8 the average 
per stomach is over 53 percent of the food. Spiders were found in 
nearly every stomach of broods 1 to 4, while the other four broods 
contained very few. These facts indicate that birds exercise com- 
paratively little choice as to the exact nature of their food, but take 
that which is nearest to hand. "With a brood of hungry vouno- iuces- 
santly clamoring for supplies little opportunity is afforded the busy 
parents to select precisely the kind of insects best adapted to the 
wants of the young. Nature teaches that insect food and not vege- 
table is needed and the gaping mouths are filled with the nearest 
obtainable supply. 

In addition to the examination of stomachs of nestling thrushes 
field observations were made on the feeding of the young by the par- 
ent birds. Two nests of this species in the town of Hayward, Cal., 
were observed during several days in June and July, 1901. Each 
nest was watched for two one-hour periods on as many days as pos- 
sible, and the number of times that the young were fed was carefully 
noted. 

It may be said, to begin with, that the stomachs of young birds are 
kept constantly full during the hours of daylight. 

Xest Xo. 1 Avas situated on a tree on the bank of a small creek on 
the edge of an orchard. When first observed, there were three young 
in the nest, apparently about five days old. This nest was watched 
for one hour from 9.40 a. m. on June 30, and the young were fed 
six times, but, as both parent birds came to the nest once with food 
in their beaks and went away without feeding the young, it is prob- 
able that they were not quite satisfied as to the intentions of the 
observer. At 4.25 p. m. of the same day another hour was spent in 
watching the nest, and the young were fed 11 times. On July 1. 
beginning at 8.30 a. m., 7 feedings occurred in one hour. This nest 
was not again watched until July 3 at 8.40 a. m., when the young 
were fed S times during the hour. In the afternoon of the same day, 
beginning at 3 o'clock, 12 feedings were observed in one hour. The 
last observation of this nest was made on July 5, beginning at 9 a. m. 
In an hour L3 visits with food were noted. In the case of this brood 
there were 57 feeding- in six hours, or an average of 9| feeding- per 
hour. As there were three young, each one musl have been fed a lit- 
tle more than three time- per hour. 

Nesl No. 2 also contained three young, hut they were only about 
•J days old when first visited. The first observation was on June 30, 



i,.\ vi I a I CH BBS. 91 

;ii 3.20 p. in., and the following hour the young were fed s times, 
and as the weather was cold the mother bird spenl a number of min 
utes on the nest warming the nestlings. On July 1 another hour was 
spent in watching the nest, beginning al 9.30 a. m., and only 1 feed- 
Lngs were observed. It was, however, a cold, windy morning, and 
one or other of the parent birds remained on the nest al] the time, 
leaving only when the mate brought food and took its turn brooding. 
The necessity for keeping the nestlings warm evidently prevented the 
parents from feeding them as often as customary. On the morning 
of July 3, although the weather was -till rather cool, the birds 
seemed to be making up for the -canty feeding of the previous day-, 
for they were observed to feed the young \-> times in an hour, begin- 
ning at 9.40 a. in., although they still took turn- in warming the 
young for a few minutes at a tunc. In the afternoon of the same day. 
beginning at I o'clock. s fee lino- were noted in an hour. On July 5, 
beginning at L0 a. m., the parent- were seen to feed the nestlings no 
fewer than L8 times, although one of them spent several minutes 
upon the nest three times during the hour. In the afternoon of that 
day 11 feedings were noted, in the hour beginning at 3.30, and 3 
times one of the parent- brooded the young, remaining once for six 
minutes. The next observation on this nest was made on July 6, 
during the hour from 7.50 a. m., and 12 feedings were noted. On 
July 7 the last observation was made, beginning at 3.20 p. m., and 11 
feedings were noted. In this case there were 87 feedings in eight 
hour-, or an average of nearly 11 per hour. 

Considering both nests together, as each had the same number of 
young, we have 144 feedings in fourteen hours. Now at this time of 
year there arc just about fourteen hours of available daylight, so that 
144 feedings may be considered as an average day's work for a pair 
of parent bird-, and as signifying the destruction of at least 144 
insects, probably several times that number. Each of the three 
young must have been fed 48 times, which means that each stomach 
was filled to it- full capacity several times during the day, another 
illustration of the fact that the digestion and assimilation of bird-. 
especially of young ones, is constant and verj rapid. Thi- i- further 
shown by the Tact that when attempt- have been made to raise young 
birds the experiment- in most cases have failed because the nestlings 
were not fed often enough and actually starved to death. Young 
bird- thrive best when fed a small quantity of food at short intervals 
rather than greater quantities at Longer periods. 

SI \l \l.\in . 

From the foregoing it appear- that although thi- thrush eats con- 
siderable fruit it is not a pest to the fruit grower. Cherries seem to 



92 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

be the only kind eaten to any considerable extent, and in the later 
summer wild fruit forms a large part of its vegetable diet. This 
thrush does not aid in the destruction of the seeds of noxious weeds. 
In its insect diet the russet-back thrush is almost wholly beneficial, 
as it eats but few predaceous beetles or other useful insects. As 
young thrushes are fed almost exclusively upon insects, and a? they 
eat almost continuously from morning till night, they must destroy 
an enormous number of these harmful creatures. From our present 
knowledge of its food and general habits, the russet -back thrush must 
be considered as one of our positively beneficial birds. 

HERMIT THRUSH. 
(Hylocichla guttata.) 

The hermit thrush occurs in the valley and foothill parts of Cali- 
fornia only as a winter visitant. Thus it can destroy no fruit, except 
perhaps olives, and thus far no complaints have been made against 
the species in this respect. Although the bird has not yet attracted 
attention by depredations upon fruit, it may be well, nevertheless, 
to glance at its food habits as indicated by the contents of 08 stomachs. 
These were mostly taken in or about the Bay region, while a few 
came from the southern part of the State. Examination of the con- 
tents of these stomachs shows animal matter to the extent of 56 
percent and vegetable 44 percent. The proportion of the two 
elements varies little in the different months. 

Animal food. — Hymenoptera, mostly ants, constitute the largest 
item of the insect food. They amount to 24 percent, and appear to 
be eaten regularly in every month. This record is better than that 
of the russet-back. Caterpillars come next in importance, and form 
10 percent of the food. They seem to be eaten rather more freely 
in February and March than in other months, though they are taken 
at all times of year. Predatory beetles (Carabidae) are noticeable by 
their absence, as only a few remains of them appear. Beetles of other 
families, all harmful species, form 11 percent of the food. Weevils, 
or snout-beetles (Rhynchophora) , constitute more than two-thirds 
of these, which would seem to indicate that they are a favorite food. 
When we consider that the carabids live on the ground, and are the 
most abundant and most easily obtained of any of the common 
beetles, and note how few of them the hermit thrush eats, while on 
the other hand it eats many snout-beetles, which. living to a great 
extent on tree-, are generally much more difficult to find, we are 
forced to the conclusion that the latter are a preferred food, and that 
they are purposely -ought for. Other insects, with some spiders and 
a few miscellaneous article- of diet (Oniscus), amount to about 12 



WESTERN robin. 93 

percent. As in the case of the russet-back thrush, one stomach of the 
hermit contained the bones of a salamander. 

Vegetable food.- -The vegetable food is made up of two principal 
components — fruit and seeds. The former amounts to 29 percent 
of the whole and is composed of wild species, or of old fruit Left on 
trees and vines. A few stomachs contained seeds of raspberries, 
which, of course, must have been old, dried-up fruit. Seed- of the 
pepper tree and mistletoe were the mosl abundant and. with sonic 
unidentifiable pulp and -kins, make up the complement of fruit. The 
hermit thrush eats more seeds than the russet-back, but doe- not 
stand high a- a weed destroyer. Seed- of all kinds amount to II 
pci-ccnt of tin 1 food, hut only a few are usually reckoned a- weed seeds. 
The most abundant seed was poison oak {Rhus diversiloba) , which 
was found in a number of stomachs. While this plant i- not usually 
classed among weeds, it is really a weed of the worst description, 
since it is out of place no matter where it is. It is unfortunate that 
bird- in eating the seeds of this plant do not destroy them, but only 
aid in their dissemination. 

SUMMARY. 

On the whole, the food of the hermit thrush is remarkably free 
from useful product-, destruction of which is a loss to mankind. The 
worst that can be said of the bird is that it eats and scatter- the seed 
of poison oak, but it does not do this to a marked degree. 

WESTERN ROBIN. 
i Werula m i<inii<>>i<i propinqua.) 

In most of the valleys of California the robin is a winter resident 
only, and would be of little economic importance did it not possess 
a voracious appetite, the satisfaction of which occasionally leads to 
lamentable results. Of its summer food we know almost nothing, 
except what may be inferred from its list of edibles while in the 
valleys, and by comparison with the diet of its eastern relative. The 
two birds are so nearly alike that probably in the same environment 
they would cut practically the same things. 

In investigating the food of the western robin 71 stomach- were 
examined. They were taken in every month from September to 
June, inclusive, except May. This number i.- entirely ton small to be 
used a- a basis for final conclusion-, but it suffices to give ;i bint a- to 
the differences, if any there be. between the food of the eastern and 
western races. Only one stomach was taken in each of the month- of 
September. October, and June. The other- are well distributed 
through the remaining month.-. Discarding return- from the three 



94 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

months mentioned, 71 stomachs remain, from which a fairly reliable 
idea of the winter food of the robin in California may be obtained. 

In the first examination we find 40 percent of animal food to 60 
of vegetable. The food of eastern robins for the whole year con- 
tains 42 percent of animal matter to 58 percent of vegetable, and 
during the six months beginning on November 1 the amounts are: 
Animal 35 percent and vegetable 65 percent. If, however, our study 
is restricted to the three winter months, we find that the eastern robin 
eats 18 percent of animal food and 82 percent of vegetable, while 
for the same period the western one consumes 22 percent animal 
and 78 percent vegetable. These comparisons do not indicate essen- 
tial differences in the food of the two birds. The western bird eats 
more insects during the winter months because on the west coast 
insects are more abundant and more easily obtained at that season 
than in the East. Confining attention, however, to the six months 
beginning with November, the eastern bird eats a greater percentage 
of insects. It is almost certain that if the material were at hand to 
illustrate the food of the western robin during the remainder of 
the year, the bird would be found to eat a much larger percentage 
of insects than in the six months covered by this investigation. 

Animal food. — Beetles of various families are the largest item of 
animal food. The greater number were eaten in April, when they 
amount to over 54 percent of the whole food for the month. They 
were distributed among several families, but the most conspicuous 
were the snout-beetles, or weevils, which aggregated 25 percent. 
This is a favorable showing for the robin, for these beetles are among 
the most harmful insects with which the fruit grower- and farmers 
have to contend. The average percentage of beetles for the whole 
six months is about 13 percent of the food. Caterpillars are next in 
order of abundance and amount to over 4 percent. The remainder of 
the animal food is made up of various insects, of which no order 
claims preeminence, and of a few angleworms. 

Vegetable food. — The bulk of the vegetable food from November 
onward is cultivated fruit. After this month it gradually falls off, 
and very little was found in stomachs collected in March and April. 
"With the exception of olives, the bird can obtain no fruit of value 
after the 1st of November, and as olive- wen' not identified in any of 
the stomachs it i- probable that most of the fruit consumed was 
worthless, having been left after the crop was gathered. The follow- 
ing fruits were identified: Grapes in 5 stomachs, figs in 3, prune- in 
2, pear, apple, and blackberries in 1 each. Of wild fruit, pepper ber- 
ries were found in 17 stomachs, mistletoe berries in -J. and fruit not 
positively identified in 11. Pepper berries evidently are the favorite, 
since not only were they found in the greater number of stomachs, 
hut 1 stomach contained 2 1 and another 2 s of these berries. Two 



WESTERN ROBIN. ( .». r > 

stomachs contained wheal and 3 had weed seeds, bin* dry seeds are evi- 
dently not favorite food with the robin. 

Destruction of olives. From the foregoing the robin would not 
appear to do much damage, or al least nol more than is amply paid 
for by the insects it destroys. But, unfortunately, more is to be said 
about its food habits, which does not redound so much to its credit. 
In certain years when their customary food is scarce, robins appear 
in the valley- in immense numbers, and wherever there are olives 
they eat them so eagerly and persistently that the loss is often serious 
and occasionally disastrous. Sometimes, indeed, ii is only by the 
most strenuous efforts, with considerable outlay of labor and money, 
that any part of the crop can be saved. Fortunately, such extensive 
damage is not done everj year, although here and there the olive 
crop may suffer. 

There is probably no more striking example of exceptional and 
intermittent damage to fruit by birds than an instance 1 which occurred 
in the winter of L900 L901. In that year the olive orchard- in 
various parts of California were invaded by immense numbers of 
robins, which ate the fruit and in some instances destroyed the whole 
crop. In orchard- where persistent effort was made to destroy and 
drive them away they -till ruined from one-fourth to one-half of the 
yield. Olive orchards in Santa Clara Valley especially were afflicted. 
Mr. Paid Masson, who owns two orchards near Saratoga, as quoted 
by the San Jose Mercury of January 17. L901, -ays: 

In my largesl orchard of about 500 trees adjoining a larger orchard of about 
50 acres on the El Quito farm, which is owned by E. E. Goodrich, are thousands 
of robins, which are destroying all the fruit on the trees. About two mouths 
ago I estimated that my trees would yield about 4 tons of olives, but Sunday, 
when I visited my orchard, I found the fruit would not be worth picking. 

I killed some of the robins, and upon examination found as many as five or 
six whole olives in the crop of each bird. Besides those which the bird had 
swallowed whole, many olives are pecked so that they are spoiled for market. 
Sniid.iN there were qo1 less than 50,000 robins on my place, and they are equally 
as plenl it'nl on El Quito farm. 

Mr. Edward E. Goodrich, the owner of El Quito farm and olive 
orchard, quoted by the same authority, says: 

The so-called robin is a destructive pes! to an olive orchard. A crop can not 
be saved when the migration of the robin corresponds exactly with the maturity 
of the olive, as it does this year, excepl by immediate picking, which is prac- 
tically impossible, or by shooting so constantly as to prevenl steady consump 
tion. :: In 1898 my crop was L30 tons, and should have made about 

l.iieo gallons of oil. Owing to the lack of rain the resuH was about 2,750 gal- 
lons, of the value of $1 1,000. Now, that crop could bave been wiped ou1 in ten 
days by robins if they bad been here as they were this season and do shooting 
had been done. So far as my foreman could estimate, before the birds 
descended upon the place, he pined the crop at a probable 3,000 gallons, which 
means when sold from $12,000 to $16,000, according to prices, and thai would 
have been utterly destroyed but for the constanl shooting the last ten days. 



96 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

As it was. Mr. Goodrich placed his loss on the olive crop through 
the devastations of the robins at 25 percent of the whole, or about 
$5,000, while his foreman, in an interview with the writer, estimated 
the loss at 50 percent. He stated also that robins were so numerous 
that he killed 7 in a tree at a single shot. 

The San Jose Mercury also states : 

A representative of the Mercury visited the El Quito olive orchard to see what 
the facts were in this matter. He found a force of men picking the fruit as 
rapidly as possible, and he also saw thousands upon thousands of robins doing 
the same thing. On his way out he occasionally saw a single bird on the fence 
or in a prune tree, but when he reached El Quito the sky was streaked with 
robins flitting about and having a gala time of it. Men were scattered about 
through the orchard with guns, and every few minutes the report of one of 
these would set the robins to flying, but in an instant they would settle down 
again and resume their feast. 

Hon. Ellwood Cooper, of Santa Barbara, one of the largest olive 
growers on the Pacific coast, in a letter dated January 25, L901, says: 

The robin is a terrible pest to olives. The birds do not always appear to come 
to the coast My first experience was some fifteen years ago. The olives were 
late in ripening. I was as late as March making oil. The robins appeared to come 
in by the thousands. My last orchard that year was about one-half mile in length. 
The pickers were at. one end. I had a man with a gun at the other, but they 
would attack the middle, and when the gunner would reach them they would 
fly to the end he left. This year they have been particularly bad. My boys 
reported that the birds, mostly robins, picked more olives than they could. JThe 
foreman of the pickers told me that he had knocked from a tree one-quarter of 
a sack and went to dinner; when he returned not an olive was on the ground. 
I know that on the ground in one orchard where the rain had caused to fall as 
many olives as would till a bushel basket, in a week not one would he seen. The 
robins do not seem to be able to pick the olives so rapidly from the trees, but 
peck at those that are commencing to dry. knock them to the ground, then gel 
them. The birds at this writing are in all my orchards by the thousands. They 
do not appear every year. It has been my theory that the native berries in the 
Sierra sumo years are not in sufficient quantities for food. 

In the last sentence Mr. Cooper lias probably suggested the true 
cause of the trouble. There is a crop of olive- every year and the 
number of robins fluctuates little, but they rarely attack olives because 
usually their native food abounds. Where this fails the hungry 
birds shift about until they find a substitute. 

SI M MARY. 

With the exception of such sporadic cases as the above, the food 
habit- <>!' the rohin are for the most part of a beneficial, or al Least 
harmless, character. In the eastern part of the country very little 
damage by the robin i> reported, though it ls one of the most abundant 
species. This is probably largely owing to the plentifulness of wild 
Pruits throughout the season. The trouble in California i- that the 
rohin- Prom an extensive region concentrate into a comparatively 



WESTERN BLUEBIRD. ( .»7 

small area and, finding an abundant supply of palatable food, feed 
upon olives to the exclusion of all other food. 

Were the hills and canyons of California as well supplied with wild 
berries as are the corresponding place- in the Appalachian region, 
it is doubtful if such devastations of the olive crop would ever occur. 

Since failure of the natural food supply of the robin is only occa- 
sional and can not be anticipated in advance, no direct safeguards 
against the bird's inroad- are possible, though the planting of pepper 
and other berry-bearing tree- about the orchard- would materially 
aid in protecting the olive crop. The prompt and unsparing use 
of the shotgun when the emergency occurs, even though it seems to be 
the only practicable method to save the crop, is much to be deprecated, 
since the destruction of robins, which in the main are useful birds, 
is a loss to the community. 

WESTERN BLUEBIRD. 
(Sialia mexicanus occidentalis.) 

The western bluebird has the same gentle, quiet demeanor that 
characterizes its relative of the Eastern States. It has not yet, per- 
haps, become quite so domestic as that species, but still is much in- 
clined to frequent orchards and the vicinity of farm buildings. 
While the eastern bluebird usually nests either in a hole of an orchard 
tree or in the box specially provided for its use, the western species 
has not yet fully abandoned its habit of utilizing forest trees as nest- 
ing sites, and often may be found in lonely canyons or among the 
hills far from the abodes of man. The orchards of California 
as vet are hardly old enough to offer many hollow trees as nesting 
places of the kind so dear to the heart of our gentle friend. There 
is no reasonable doubt that in time the western species will become 
as dome-tic as the eastern one. A nest was found by the writer in a 
hollow tree in the home orchard of a ranch, onl} 7 a few rods from the 
house. It contained six young, which would indicate that the bird 
is a prolific breeder, in this respect also resembling the eastern 
species. 

The western bluebird is less migratory than the eastern and does 
not entirely desert the United States in winter; so it- good work is 
continuous. As insects are active in California in every month the 
bird is able to support life even if there is no other food. More- 
over, the insects eaten in winter count more in the reduction of these 
pests than do those taken after the spring broods are out. [nsects 
that live through the winter are the stock by which the species is 
perpetuated, and the destruction of a few at this time is equivalent 
to the death in summer of hundreds or thousands. 
9379— No. 30—07 7 



98 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

The food of the bluebird consists of elements whose consumption 
is almost wholly a benefit to the farmer. Four-fifths of it is insect-: 
only a small portion of these are useful, and these to a limited extent. 

In the invest i gation of the food of the bluebird 1ST stomachs were 
examined. This number is not so large as could be desired, and. 
moreover, was rather irregularly distributed over the year. Only 
one stomach was obtained in May, and only one in April, while the 
number for several other months are too few. Geographically they 
fairly well represent the fruit-growing regions of the State from as 
far south as San Bernardino northward to Santa Rosa. The food 
found in the stomachs consists of animal matter. 82 percent ; vege- 
table. 18 percent. 

Animal food. — Of the animal portion a little less than 12 percent 
consists of predaceous beetles (Carabidae), which are usually reck- 
oned as useful. There are. however, many exceptions to this rule, 
and since most of the species of this family are wonderfully abun- 
dant it is not probable that the bluebird does much harm by eating 
them. It is believed, moreover, that this record of Carabidae is above 
the normal, for the one bird taken in April had eaten 90 percent of 
these beetles, thereby raising the average of the whole. In August, 
on the other hand, not one of the five birds examined had eaten a 
ca rabid. Had these months been omitted from the reckoning the 
average would have been reduced to about one-third of the present 
figure, which is probably much nearer the truth. 

Other beetles amount to over IT percent of the food, and were 
distributed among about a dozen families, all of them harmful, except 
three or four ladybirds (Coccinellidse), which are useful. 

Caterpillars evidently are a favorite food, and probably are eaten 
in every month, though evidence is wanting for April and May. 
They amount to over 17 percent of the year's food. Few of these 
insects are eaten in spring and early summer, many in fall and winter. 
As practically all caterpillars are harmful, this item of diet counts 
entirely in the bird's favor. 

Grasshoppers and crickets, mostly the former, were eaten in every 
month except April, but a greater number of stomachs would prob- 
ably give a different result. They amount to a little less than \L\ 
percenl of the year's food. They appear in the stomachs of western 
birds ai a somewhal earlier date than in those of eastern species. 
In the Atlantic and Central States, Augusi i- preeminently the season 
of Lira — hopper-, and in that month they constitute tin 1 principal 
article of diet of many species <>f birds. The western bluebird eats 
grasshoppers in March to the extent of about 11 percenl of it> food. 
In dune they amount to over 38 percent, and in July reach a maximum 
of nearly li> percent, or nearly half of all that it eats. In September 
they amount to 1<) percent, but decrease rapidly from that time. 



WESTERN BLUEBIRD. ( .» ( .» 

Bees and wasps (Hymenoptera) are not largely eaten b} the blue 
bird, and flies scarcely at nil. as the aggregate for the year amounts 
in only four-tent hs of 1 percent. 

In the summer bugs ( Hemiptera ) are eaten to a moderate extent. 
The species belong mostly to the family of 'soldier bugs' (Penta- 
tomidae) or, as they are sometimes called, 'stink-bugs,' for they have 
a \ ilc odor ami when taken into the inoiiili with a berry are uot agree- 
able to human taste. The total percentage of wasps, flies, bugs, and a 
few other insects is a little less than 10 percent of the whole food. 

Spiders are eaten to some extent throughout the year, but never in 
great numbers. The greatest number are taken in February, about 6 
percent. The total average \'<n- the year i- 2 percent. One stomach 
contained the lingua] ribbon of a -nail. 

Vegetabli /'<><»/. — The bluebird asks practically nothing of man in 
the way of vegetable food. It is evident that it i- not a lover of seeds, 
a- i^ the linnet, and with abundance of them at hand, eat- few of none. 
In ii stomachs several -mall unknown seeds were found, which may 
have been -wallowed accidentally. Not a kernel of grain had been 
eaten. Fruit constitutes nearly the whole vegetable portion of the 
food, and was distributed a- follows: Elderberries (Sambucus) in L9 
stomachs; grapes in L2 stomachs, all in the month of October or later: 
blackberries or raspberries (Rubus) identified in 4 stomachs; pepper 
fruits in '1 stomachs; figs in 1 and mistletoe berries in 1. Besides 
these 9 stomachs contained pulp or skins that could be identified only 
as fruit. From this it appears that elderberries are the favorite fruit 
of the bluebird. Fortunately these are nearly always to be had in 
California. Most of the grapes eaten probably were waste fruit, as 
many of them were consumed in December and other winter months. 

FOOD OF Vol NC 

Am ong the stomachs examined were those of several nestlings about 
a week old. They were of interest as showing how large a proportion 
of animal food is given to the young. In one brood of six the only 
vegetable food found was a single piece of plant stem, which was 
probably given accidentally with other food, and should properly be 
<da— ed a- rubbish. The real food consists of grasshoppers and 
crickets 90 percent, beetles 3 percent, and the remainder made-up of 
bugs, caterpillars, and spiders. In another brood of four, grass- 
hoppers and crickets constituted '.>7.."> percent of the food, and 1 
stomach contained nothing else. The remain- of 11 grasshoppers 
were found in one of these stomachs, and 1<) grasshoppers, a cricket, 
and a beetle in another. The only vegetable matter found in these 
I stomachs was a single -ceil of Polygonum. 

Besides the stomachs of the western bluebird discussed above, 11 



100 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 

stomachs of the Arctic bluebird (Sialia arctica) were obtained. 
They were taken in fall and winter, and, while so small a number is 
not sufficient for positive conclusions, it may be said that the charac- 
ter of the food closely resembles that of the other species in the same 
months. 

The two species eat about the same proportion of animal and vege- 
table food; the animal part consists of the same orders of insects, 
while the vegetable part is made up of the same varieties of fruit. 
In short, it may be said that if there are important differences in the 
food habits of the two birds the evidence at hand fails to establish 
the fact. 

SUMMARY. 

It seems scarcely necessary to comment on the foregoing statements 
with regard to the bluebird's diet in its economic relations. That the 
bird is an eminently useful species is so patent that it hardly needs to 
be pointed out. Whatever harm fruit growers have suffered from 
birds, none of it can be laid at the door of the bluebird. 

List of insects identified in stomachs of bluebirds : 

COLEOPTEKA. 

Coccinella t. californica. Blapstinus sulcatus. 

Hippodamia convergens. Blapstinus pulverulent us. 

Polycaon stout ii, Rliigopsis effracta. 

Aplwdius rugifrons. Balaninus sp. 

Blapstinus dilatatus. Sitones sp. 

HEMIPTERA. 

Saissetia olecr. Sinea diadema, 

HYMENOPTERA. 

Messor and re i (ant). 
Insects also were identified as belonging to the following families : 

COLEOPTERA. 

Carabidse. Ptinida?. 

Staphylinidse. Scarabseidse. 

Coccinellidse. Cerambycida?. 

Histeridae. Chrysomelidse. 

Elateridse. Tenebrionidse. 

Buprestidse. Rhynchophora (superfamily). 

Lampyrida?. 

HEMIPTEHA. 

Reduviidse. Corimelaenidse. 

C-ipsida'. Scutelleridae. 

Lygseidse. Jassidse. 

Pentatomidse. Coccidte. 



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